使用的教材是國@郭霖寫的《第二行代碼》

應用名：Cool Weather

一、功能需求及技術可行性分析

1、具備的功能

可以羅列出全國所有的省市縣
可以查看全國任意城市的天氣信息
可以自由地切換城市，去查看其他城市地天氣
提供手動更新以及後臺自動更新天氣的功能

2、技術可行性分析

如何獲取全國省市縣的信息：

天氣數據：和風天氣的數據接口
 省市縣數據：http://guolin.tech/api/china

編寫步驟

基本配置
創建數據庫和表
遍歷全國省市縣數據
顯示天氣數據
編寫天氣界面
將天氣顯示到界面上
獲取必應天氣壁紙
手動更新天氣
手動切換城市
後臺自動更新天氣
擴展功能【有空再寫】
修改圖標和名稱

二、正式編寫

新建一個空項目 Cool Weather

一、基本配置

配置Git，啓用版本控制
將app/build.gradle 依賴庫更新到最新

打開AndroidManifest.xml：

設置<application>屬性tools:ignore="GoogleAppIndexingWarning"【應用內打開app的功能，此功能不需要】
將<application>屬性android:allowBackup設置爲false【不允許應用內數據被取出】

二、創建數據庫和表

爲了讓項目有更好的結構，在com.coolweather.android下新建幾個包

1、添加依賴庫

    implementation 'org.litepal.android:java:3.0.0'     // 數據庫操作
    implementation "com.squareup.okhttp3:okhttp:4.3.1"  // 網絡請求
    implementation 'com.google.code.gson:gson:2.8.6'    // 解析JSON
    implementation 'com.github.bumptech.glide:glide:4.11.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0' // 加載圖片的庫
    implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.0.0'   // 下拉刷新

2、設計數據庫表的結構

在db下建立三張表 province，city，county

public class Province extends LitePalSupport {
    private int id;
    private String provinceName;
    private int provinceCode;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getProvinceName() {
        return provinceName;
    }

    public void setProvinceName(String provinceName) {
        this.provinceName = provinceName;
    }

    public int getProvinceCode() {
        return provinceCode;
    }

    public void setProvinceCode(int provinceCode) {
        this.provinceCode = provinceCode;
    }
}

public class City extends LitePalSupport {
    private int id;
    private String cityName;
    private int provinceId;
    private int cityCode;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCityName() {
        return cityName;
    }

    public void setCityName(String cityName) {
        this.cityName = cityName;
    }

    public int getProvinceId() {
        return provinceId;
    }

    public void setProvinceId(int provinceId) {
        this.provinceId = provinceId;
    }

    public int getCityCode() {
        return cityCode;
    }

    public void setCityCode(int cityCode) {
        this.cityCode = cityCode;
    }
}

public class County extends LitePalSupport {
    private int id;
    private String countyName;
    private int cityId;
    private String weatherId;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCountyName() {
        return countyName;
    }

    public void setCountyName(String countyName) {
        this.countyName = countyName;
    }

    public int getCityId() {
        return cityId;
    }

    public void setCityId(int cityId) {
        this.cityId = cityId;
    }

    public String getWeatherId() {
        return weatherId;
    }

    public void setWeatherId(String weatherId) {
        this.weatherId = weatherId;
    }
}

3、數據庫版本控制

app/src/main目錄下新建一個文件夾assets，在該目錄下建一個litepal.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<litepal>
    <dbname value="cool_weather" />

    <version value="1" />

    <list>
        <mapping class = "com.coolweather.android.db.Province" />
        <mapping class = "com.coolweather.android.db.City" />
        <mapping class = "com.coolweather.android.db.County" />
    </list>
</litepal>

引入LitePal，修改AndroidManifest:

    <application
        android:name="org.litepal.LitePalApplication"

三、遍歷全國省市縣數據

1、服務器交互

在util包下增加一個HttpUtil類，用於服務器交互：

public class HttpUtil {
    public static void sendOkHttpRequest(String address, okhttp3.Callback callback){
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder().url(address).build();
        client.newCall(request).enqueue(callback);
    }
}

2、解析JSON

增加一個Utility類，便於解析json數據：

public class Utility {
    // 解析省級數據
    public static boolean handleProvinceResponse(String response){
        if(!TextUtils.isEmpty(response)){
            try{
                JSONArray allProvinces = new JSONArray(response);
                for (int i = 0; i < allProvinces.length(); i++){
                    JSONObject provinceObject = allProvinces.getJSONObject(i);
                    Province province = new Province();
                    province.setProvinceName(provinceObject.getString("name"));
                    province.setProvinceCode(provinceObject.getInt("id"));
                    province.save();
                }
                return true;
            }catch (JSONException e){
                e.printStackTrace();
            }
        }
        return false;
    }
    
    // 解析市級數據
    public static boolean handleCityResponse(String response, int provinceId){
        if(!TextUtils.isEmpty(response)){
            try {
                JSONArray allCities = new JSONArray(response);
                for(int i = 0; i < allCities.length(); i++){
                    JSONObject cityObject = allCities.getJSONObject(i);
                    City city = new City();
                    city.setCityName(cityObject.getString("name"));
                    city.setCityCode(cityObject.getInt("id"));
                    city.setProvinceId(provinceId);
                    city.save();
                }
                return true;
            }catch (JSONException e){
                e.printStackTrace();
            }
        }
        return false;
    }
    
    // 解析縣級數據
    public static boolean handleCountyResponse(String response, int cityId){
        if(!TextUtils.isEmpty(response)){
            try {
                JSONArray allCounties = new JSONArray(response);
                for(int i = 0; i < allCounties.length(); i++){
                    JSONObject countyObject = allCounties.getJSONObject(i);
                    County county = new County();
                    county.setCityId(cityId);
                    county.setCountyName(countyObject.getString("name"));
                    county.setWeatherId(countyObject.getString("weather_id"));
                    county.save();
                }
                return true;
            }catch (JSONException e){
                e.printStackTrace();
            }
        }
        return false;
    }
}

3、選擇地區的佈局

choose_area.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#fff">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/title_text"
            android:layout_centerInParent="true"
            android:textColor="#fff"
            android:textSize="20sp"/>

        <Button
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:id="@+id/back_button"
            android:layout_marginLeft="10dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:background="@drawable/ic_back"
            android:layout_marginStart="10dp"
            android:layout_alignParentStart="true" />

    </RelativeLayout>

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/list_view"/>

</LinearLayout>

4、遍歷省市縣的碎片

public class ChooseAreaFragment extends Fragment {
    public static final int LEVEL_PROVINCE = 0;
    public static final int LEVEL_CITY = 1;
    public static final int LEVEL_COUNTY = 2;

    private ProgressDialog progressDialog;
    private TextView titleText;
    private Button backButton;
    private ListView listView;
    private ArrayAdapter<String> adapter;
    private List<String> dataList = new ArrayList<>();

    private List<Province> provinceList;
    private List<City> cityList;
    private List<County> countyList;
    private Province selectedProvince;
    private City selectedCity;
    private int currentLevel;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.choose_area, container, false);
        titleText = view.findViewById(R.id.title_text);
        backButton = view.findViewById(R.id.back_button);
        listView = view.findViewById(R.id.list_view);
        assert getContext()!= null;
        adapter = new ArrayAdapter<>(getContext(), android.R.layout.simple_list_item_1, dataList);
        listView.setAdapter(adapter);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if(currentLevel == LEVEL_PROVINCE){
                    selectedProvince = provinceList.get(position);
                    queryCities();
                }else if(currentLevel == LEVEL_CITY){
                    selectedCity = cityList.get(position);
                    queryCounties();
                }
            }
        });
        backButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(currentLevel == LEVEL_COUNTY){
                    queryCities();
                }else if(currentLevel == LEVEL_CITY){
                    queryProvinces();
                }
            }
        });
        queryProvinces();
    }

    /*c查詢全國的所有的省，優先從數據庫查詢，沒有則到服務器上查詢*/
    private void queryProvinces(){
        titleText.setText("中國");
        backButton.setVisibility(View.GONE);
        provinceList = LitePal.findAll(Province.class);
        if(provinceList.size() > 0){
            dataList.clear();
            for (Province province : provinceList){
                dataList.add(province.getProvinceName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            currentLevel = LEVEL_PROVINCE;
        }else {
            String address = "http://guolin.tech/api/china";
            queryFromServer(address, "province");
        }
    }

    /*查詢省內所有的市，優先從數據庫查詢*/
    private void queryCities(){
        titleText.setText(selectedProvince.getProvinceName());
        backButton.setVisibility(View.VISIBLE);
        cityList = LitePal.where("provinceId = ?", String.valueOf(selectedProvince.getId())).find(City.class);
        if (cityList.size() > 0){
            dataList.clear();
            for (City city : cityList){
                dataList.add(city.getCityName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            currentLevel = LEVEL_CITY;
        }else {
            int provinceCode = selectedProvince.getProvinceCode();
            String address = "http://guolin.tech/api/china/" + provinceCode;
            queryFromServer(address, "city");
        }
    }

    /*查詢選中市內的所有縣，優先從數據庫查詢*/
    private void queryCounties(){
        titleText.setText(selectedCity.getCityName());
        backButton.setVisibility(View.VISIBLE);
        countyList = LitePal.where("cityId = ?", String.valueOf(selectedCity.getId())).find(County.class);
        if (countyList.size() > 0){
            dataList.clear();
            for (County county : countyList){
                dataList.add(county.getCountyName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            currentLevel = LEVEL_COUNTY;
        }else {
            int provinceCode = selectedProvince.getProvinceCode();
            int cityCode = selectedCity.getCityCode();
            String address = "http://guolin.tech/api/china/" + provinceCode + "/" +cityCode;
            queryFromServer(address, "county");
        }
    }

    private void queryFromServer(String address, final String type){
        showProgressDialog();
        HttpUtil.sendOkHttpRequest(address, new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                // 回到主線程處理邏輯
                getActivity().runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        closeProgressDialog();
                        Toast.makeText(getContext(), "加載失敗", Toast.LENGTH_SHORT).show();
                    }
                });
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String responseText = response.body().string();
                boolean result = false;
                if ("province".equals(type)){
                    result = Utility.handleProvinceResponse(responseText);
                }else if("city".equals(type)){
                    result = Utility.handleCityResponse(responseText, selectedProvince.getId());
                }else if("county".equals(type)){
                    result = Utility.handleCountyResponse(responseText, selectedCity.getId());
                }
                if (result){
                    getActivity().runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            closeProgressDialog();
                            if ("province".equals(type)){
                                queryProvinces();
                            }else if("city".equals(type)){
                                queryCities();
                            }else if("county".equals(type)){
                                queryCounties();
                            }
                        }
                    });
                }
            }
        });
    }

    /*顯示進度對話框*/
    private void showProgressDialog(){
        if (progressDialog == null){
            progressDialog = new ProgressDialog(getActivity());
            progressDialog.setMessage("正在加載");
            progressDialog.setCanceledOnTouchOutside(false);
        }
        progressDialog.show();
    }

    /* 關閉進度對話框*/
    private void closeProgressDialog(){
        if(progressDialog != null){
            progressDialog.dismiss();
        }
    }
}

5、佈局中引入碎片

主佈局

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:name="com.coolweather.android.ChooseAreaFragment"
        android:id="@+id/choose_area_fragment"/>

</FrameLayout>

去除原生標題欄，修改res/values/styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

</resources>

6、聲明權限

<uses-permission android:name="android.permission.INTERNET"/>

如果是安卓Q版本，還要給<application>設置屬性

android:usesCleartextTraffic="true"

7、展示

四、顯示天氣數據

1、基本格式

天氣數據返回的內容非常多，但解析數據只要一行代碼，但前提是將數據對應的實體類建立好，查詢開發文檔，得到三個請求分別爲：
請求參數爲now：

{
	"HeWeather6": [
		{
			"basic": {},
			"update": {},
			"status": "ok",
			"now": {},
		},
	]
}

請求參數爲forecast:

{
	"HeWeather6": [
		{
			"basic": {},
			"update": {},
			"status": "ok",
			"daily_forecast": []
		},
	]
}

請求參數爲life_style:

{
	"HeWeather6": [
		{
			"basic": {},
			"update": {},
			"status": "ok",
			"lifestyle": []
		},
	]
}

2、建立關係

basic示例：

"basic": {
			"cid": "CN101010100",
			"location": "北京",
			"parent_city": "北京",
			"admin_area": "北京",
			"cnty": "中國",
			"lat": "39.90498734",
			"lon": "116.4052887",
			"tz": "+8.00"
		}

對應Basic類：

public class Basic {
    @SerializedName("location")
    public String cityName;

    @SerializedName("cid")
    public String weatherId;
}

update示例：

"update": {
			"loc": "2019-06-05 22:39",
			"utc": "2019-06-05 14:39"
		}

對應Update類：

public class Update {
    @SerializedName("loc")
    public String updateTime;
}

以此類推：

public class Now {
    @SerializedName("tmp")
    public String temperature;

    @SerializedName("cond_txt")
    public String info;

    @SerializedName("wind_dir")
    public String directionOfWind;

    @SerializedName("wind_sc")
    public String powerOfWind;

    @SerializedName("hum")
    public String humidity;

    @SerializedName("vis")
    public String visibility;
}

public class Forecast {
    public String date;

    @SerializedName("sr")
    public String sunrise;

    @SerializedName("ss")
    public String sunset;

    public String tmp_max;
    public String tmp_min;

    @SerializedName("con_txt_d")
    public String weatherDay;

    @SerializedName("con_txt_n")
    public String weatherNight;

    @SerializedName("pop")
    public String precipitationProbability;
}

public class LifeStyle {
    public String type;
    public String brf;
    public String txt;
}

最後用一個Weather類把所有類串起來：

public class Weather {
    public Basic basic;
    public Update update;
    public String status;
    public Now now;

    @SerializedName("daily_forecast")
    public List<Forecast> forecastList;

    @SerializedName("lifestyle")
    public List<LifeStyle> lifeStyleList;

}

五、編寫天氣界面

所有的天氣信息將在同一個界面顯示，新建一個WeatherActivity，佈局指定爲activity_weather.xml

1、頭佈局

新建頭佈局title.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/title_city"
        android:layout_centerInParent="true"
        android:textColor="#fff"
        android:textSize="20sp"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/title_update_time"
        android:layout_marginRight="10dp"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:textColor="#fff"
        android:textSize="16sp"
        android:layout_alignParentEnd="true"
        android:layout_marginEnd="10dp"
        tools:ignore="RelativeOverlap" />

</RelativeLayout>

2、當前天氣佈局

再來個now.xml作爲當前天氣信息的佈局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end"
        android:textColor="#fff"
        android:textSize="60sp"
        android:id="@+id/degree_text"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/weather_info_text"
        android:layout_gravity="end"
        android:textSize="20sp"
        android:textColor="#fff"/>

</LinearLayout>

3、未來天氣佈局

未來天氣的佈局forecast.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical" 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:background="#8000">
    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="15dp"
        android:text="預報"
        android:textColor="#fff"
        android:textSize="20sp"
        android:layout_marginStart="15dp"
        tools:ignore="HardcodedText" />
    
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:id="@+id/forecast_layout">
    </LinearLayout>

</LinearLayout>

4、未來天氣子項佈局

未來天氣的子項佈局forecast_item：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp">

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:id="@+id/date_text"
        android:layout_weight="2"
        android:textColor="#fff"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:id="@+id/info_text"
        android:layout_gravity="center_vertical"
        android:gravity="center"
        android:textColor="#fff"/>

    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:id="@+id/max_text"
        android:layout_weight="1"
        android:layout_gravity="center_vertical"
        android:gravity="right"
        android:textColor="#fff"
        tools:ignore="RtlHardcoded" />
    
    <TextView
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:id="@+id/min_text"
        android:layout_weight="1"
        android:layout_gravity="center_vertical"
        android:gravity="right"
        android:textColor="#fff"
        tools:ignore="RtlHardcoded" />


</LinearLayout>

5、空氣質量佈局

空氣質量的佈局aqi.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:background="#8000">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="15dp"
        android:text="空氣質量"
        android:textColor="#fff"
        android:textSize="20sp"
        android:layout_marginStart="15dp"
        tools:ignore="HardcodedText" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="15dp">

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1">

            <LinearLayout
                android:orientation="vertical"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true">
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:id="@+id/hum_text"
                    android:textColor="#fff"
                    android:textSize="40sp"/>
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:text="空氣溼度"
                    android:textColor="#fff"
                    tools:ignore="HardcodedText" />
            </LinearLayout>

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1">

            <LinearLayout
                android:orientation="vertical"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:textColor="#fff"
                    android:textSize="40sp"
                    android:id="@+id/wind_text"/>
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:text="風向"
                    android:textColor="#fff"
                    tools:ignore="HardcodedText" />                

            </LinearLayout>

        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

6、生活建議佈局

然後是生活建議suggestions.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical" 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:background="#8000">
    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="15dp"
        android:text="生活建議"
        android:textColor="#fff"
        android:textSize="20sp"
        tools:ignore="HardcodedText"
        android:layout_marginStart="15dp" />
    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:textColor="#fff"
        android:id="@+id/comfort_text"/>    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:textColor="#fff"
        android:id="@+id/car_wash_text"/>    
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="15dp"
        android:textColor="#fff"
        android:id="@+id/sport_text"/>

</LinearLayout>

7、合併佈局

最後把它們引入到activity_weather.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars = "none"
        android:overScrollMode="never"
        android:id="@+id/weather_layout">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <include layout="@layout/title"/>
            <include layout="@layout/now" />
            <include layout="@layout/forecast" />
            <include layout="@layout/aqi"/>
            <include layout="@layout/suggestions" />


        </LinearLayout>

    </ScrollView>

</FrameLayout>

六、將天氣顯示到界面上

1、解析服務器JSON數據

在Utility類中添加一個用於解析天氣 JSON 數據的方法：

public class Utility {
。。。。。。

    // 將返回的數據解析成實體類
    public static Weather handleWeatherResponse(String response, Weather weather, String cate){
        try{
            JSONObject jsonObject = new JSONObject(response);
            JSONArray jsonArray = jsonObject.getJSONArray("HeWeather6");
            String weatherContent = jsonArray.getJSONObject(0).toString();
            if ("now".equals(cate)){
                Now nowWeather = new Gson().fromJson(weatherContent, Now.class);
                weather.basic = nowWeather.basic;
                weather.update = nowWeather.update;
                weather.now = nowWeather.now;
                weather.status = nowWeather.status;
                return weather;
            }else if("forecast".equals(cate)){
                Forecast forecastWeather = new Gson().fromJson(weatherContent, Forecast.class);
                weather.forecastList = forecastWeather.forecastList;
                weather.status = forecastWeather.status;
            }else if("lifestyle".equals(cate)){
                LifeStyle lifeStyleWeather = new Gson().fromJson(weatherContent, LifeStyle.class);
                weather.lifestyleList = lifeStyleWeather.lifestyleList;
                weather.status = lifeStyleWeather.status;
            }
            return weather;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
}

2、在活動中處理數據

public class WeatherActivity extends AppCompatActivity {
    private ScrollView weatherLayout;
    private TextView titleCity;
    private TextView titleUpdateTime;
    private TextView degreeText;
    private TextView weatherInfoText;
    private LinearLayout forecastLayout;
    private TextView humText;
    private TextView windText;
    private TextView comfortText;
    private TextView drsgText;
    private TextView sportText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_weather);

        // 初始化控件
        weatherLayout = findViewById(R.id.weather_layout);
        titleCity = findViewById(R.id.title_city);
        titleUpdateTime = findViewById(R.id.title_update_time);
        weatherInfoText = findViewById(R.id.weather_info_text);
        forecastLayout = findViewById(R.id.forecast_layout);
        humText = findViewById(R.id.hum_text);
        windText = findViewById(R.id.wind_text);
        comfortText = findViewById(R.id.comfort_text);
        drsgText = findViewById(R.id.drsg_text);
        sportText = findViewById(R.id.sport_text);
        degreeText = findViewById(R.id.degree_text);

        Weather weather = new Weather();
        SharedPreferences prefs = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE);
        String nowString = prefs.getString("now", null);
        String forecastString = prefs.getString("forecast", null);
        String lifestyleString = prefs.getString("lifestyle", null);
        if(TextUtils.isEmpty(nowString) || TextUtils.isEmpty(forecastString) || TextUtils.isEmpty(lifestyleString)){
            // 無緩存時去服務器查詢天氣
            String weatherId = getIntent().getStringExtra("weather_id");
            weatherLayout.setVisibility(View.INVISIBLE);
            requestWeather(weatherId, weather, "now");
        }else{
            // 有緩存時直接讀取數據
            weather = Utility.handleWeatherResponse(nowString, weather, "now");
            weather = Utility.handleWeatherResponse(forecastString, weather, "forecast");
            weather = Utility.handleWeatherResponse(lifestyleString, weather, "lifestyle");
            assert weather != null;
            showWeatherInfo(weather);
        }
    }
    // 構造Url
    private String reUrl(String cate, String weatherId){
        String key = "cd9034ce70ad477b8454b6638261f0a5";
        return "https://free-api.heweather.net/s6/weather/" + cate + "?location=" + weatherId + "&key=" + key;
    }


    // 根據天氣 id 查詢城市天氣
    public void requestWeather(final String weatherId, final Weather weather,final String cate){
        String requestUrl = reUrl(cate, weatherId);
        Log.d("UUU", requestUrl);
        HttpUtil.sendOkHttpRequest(requestUrl, new Callback() {
            @Override
            public void onFailure(@NotNull final Call call, @NotNull IOException e) {
                e.printStackTrace();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        switch (cate) {
                            case "now":
                                Toast.makeText(WeatherActivity.this, "獲取今天天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "lifestyle":
                                Toast.makeText(WeatherActivity.this, "獲取生活指數失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "forecast":
                                Toast.makeText(WeatherActivity.this, "獲取預報天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                        }
                    }
                });
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                final String responseText = response.body().string();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if ((weather != null && "ok".equals(weather.status)) || ("now".equals(cate))){
                            SharedPreferences.Editor editor = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                            Weather weather_new = Utility.handleWeatherResponse(responseText, weather, cate);
                            editor.putString(cate, responseText);
                            editor.apply();
                            switch (cate) {
                                case "now":
                                    requestWeather(weatherId, weather_new, "forecast");
                                    break;
                                case "forecast":
                                    requestWeather(weatherId, weather_new, "lifestyle");
                                    break;
                                case "lifestyle":
                                    assert weather_new != null;
                                    showWeatherInfo(weather_new);
                                    break;
                            }
                        }else {
                            Toast.makeText(WeatherActivity.this, "請求到的數據出錯", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        });
    }

    // 處理並展示實體類 Weather 的數據
    private void showWeatherInfo(Weather weather){
        String cityName = weather.basic.cityName;
        String updateTime = weather.update.updateTime;
        String degree = weather.now.temperature + "℃";
        String weatherInfo = weather.now.info;

        titleCity.setText(cityName);
        titleUpdateTime.setText(updateTime);
        degreeText.setText(degree);
        weatherInfoText.setText(weatherInfo);
        forecastLayout.removeAllViews();
        for (Forecast.forecast forecast: weather.forecastList){
            View view= LayoutInflater.from(this).inflate(R.layout.forecast_item, forecastLayout, false);
            TextView dateText = view.findViewById(R.id.date_text);
            TextView infoText = view.findViewById(R.id.info_text);
            TextView maxText = view.findViewById(R.id.max_text);
            TextView minText = view.findViewById(R.id.min_text);
            dateText.setText(forecast.date);
            if (forecast.day.equals(forecast.night)){
                infoText.setText(forecast.day);
            }else {
                infoText.setText(String.format("%s轉%s", forecast.day, forecast.night));
            }
            maxText.setText(forecast.tmp_max);
            minText.setText(forecast.tmp_min);
            forecastLayout.addView(view);
        }
        if(weather.now != null){
            humText.setText(weather.now.humidity);
            windText.setText(weather.now.directionOfWind);
        }
        for(LifeStyle.lifestyle lifestyle: weather.lifestyleList){
            if ("comf".equals(lifestyle.type)){
                comfortText.setText(String.format("舒適度：%s", lifestyle.txt));
            }
            if ("drsg".equals(lifestyle.type)){
                drsgText.setText(String.format("穿衣指數：%s", lifestyle.txt));
            }
            if ("sport".equals(lifestyle.type)){
                sportText.setText(String.format("運動建議：%s", lifestyle.txt));
            }
        }
        weatherLayout.setVisibility(View.VISIBLE);
    }
}

3、從省市縣列表跳轉到天氣頁面

修改ChooseAreaFragment.java

	@Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if(currentLevel == LEVEL_PROVINCE){
                    selectedProvince = provinceList.get(position);
                    queryCities();
                }else if(currentLevel == LEVEL_CITY){
                    selectedCity = cityList.get(position);
                    queryCounties();
                }else if(currentLevel == LEVEL_COUNTY){
                    String weatherId = countyList.get(position).getWeatherId();
                    Intent intent = new Intent(getActivity(), WeatherActivity.class);
                    intent.putExtra("weather_id", weatherId);
                    startActivity(intent);
                    getActivity().finish();
                }
            }
        });
        backButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(currentLevel == LEVEL_COUNTY){
                    queryCities();
                }else if(currentLevel == LEVEL_CITY){
                    queryProvinces();
                }
            }
        });
        queryProvinces();
    }

4、選擇啓動頁面

MainActivity判斷緩存數據來決定：:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SharedPreferences prefs = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE);
        if (prefs.getString("lifestyle", null) != null){
            Intent intent = new Intent(this, WeatherActivity.class);
            startActivity(intent);
            finish();
        }
    }
}

5、展示

七、獲取必應天氣壁紙

用http://guolin.tech/api/bing_pic這個接口可以得到每日壁紙的url

1、天氣佈局修改

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/bing_pic_img"
        android:scaleType="centerCrop"/>

    <ScrollView
    ......

2、加載每日壁紙

WeatherActivity.java

public class WeatherActivity extends AppCompatActivity {
    private ScrollView weatherLayout;
    private TextView titleCity;
    private TextView titleUpdateTime;
    private TextView degreeText;
    private TextView weatherInfoText;
    private LinearLayout forecastLayout;
    private TextView humText;
    private TextView windText;
    private TextView comfortText;
    private TextView drsgText;
    private TextView sportText;
    private ImageView bingPicImg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_weather);

        // 初始化控件
        weatherLayout = findViewById(R.id.weather_layout);
        titleCity = findViewById(R.id.title_city);
        titleUpdateTime = findViewById(R.id.title_update_time);
        weatherInfoText = findViewById(R.id.weather_info_text);
        forecastLayout = findViewById(R.id.forecast_layout);
        humText = findViewById(R.id.hum_text);
        windText = findViewById(R.id.wind_text);
        comfortText = findViewById(R.id.comfort_text);
        drsgText = findViewById(R.id.drsg_text);
        sportText = findViewById(R.id.sport_text);
        degreeText = findViewById(R.id.degree_text);
        bingPicImg = findViewById(R.id.bing_pic_img);


        Weather weather = new Weather();
        SharedPreferences prefs = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE);
        String bingPic = prefs.getString("bing_pic", null);
        if(bingPic != null){
            Glide.with(this).load(bingPic).into(bingPicImg);
        }else {
            loadBingPic();
        }
        String nowString = prefs.getString("now", null);
        String forecastString = prefs.getString("forecast", null);
        String lifestyleString = prefs.getString("lifestyle", null);
        if(TextUtils.isEmpty(nowString) || TextUtils.isEmpty(forecastString) || TextUtils.isEmpty(lifestyleString)){
            // 無緩存時去服務器查詢天氣
            String weatherId = getIntent().getStringExtra("weather_id");
            weatherLayout.setVisibility(View.INVISIBLE);
            requestWeather(weatherId, weather, "now");
        }else{
            // 有緩存時直接讀取數據
            weather = Utility.handleWeatherResponse(nowString, weather, "now");
            weather = Utility.handleWeatherResponse(forecastString, weather, "forecast");
            weather = Utility.handleWeatherResponse(lifestyleString, weather, "lifestyle");
            assert weather != null;
            showWeatherInfo(weather);
        }
    }

    // 加載每日一圖
    private void loadBingPic() {
        String requestBingPic = "http://guolin.tech/api/bing_pic";
        HttpUtil.sendOkHttpRequest(requestBingPic, new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                Toast.makeText(WeatherActivity.this, "壁紙加載出錯", Toast.LENGTH_SHORT).show();
                e.printStackTrace();
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                final String bingPic = response.body().string();
                SharedPreferences.Editor editor = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                editor.putString("bing_pic", bingPic);
                editor.apply();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Glide.with(WeatherActivity.this).load(bingPic).into(bingPicImg);
                    }
                });
            }
        });
    }

    // 構造Url
    private String reUrl(String cate, String weatherId){
        String key = "cd9034ce70ad477b8454b6638261f0a5";
        return "https://free-api.heweather.net/s6/weather/" + cate + "?location=" + weatherId + "&key=" + key;
    }


    // 根據天氣 id 查詢城市天氣
    public void requestWeather(final String weatherId, final Weather weather,final String cate){
        String requestUrl = reUrl(cate, weatherId);
        HttpUtil.sendOkHttpRequest(requestUrl, new Callback() {
            @Override
            public void onFailure(@NotNull final Call call, @NotNull IOException e) {
                e.printStackTrace();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        switch (cate) {
                            case "now":
                                Toast.makeText(WeatherActivity.this, "獲取今天天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "lifestyle":
                                Toast.makeText(WeatherActivity.this, "獲取生活指數失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "forecast":
                                Toast.makeText(WeatherActivity.this, "獲取預報天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                        }
                    }
                });
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                final String responseText = response.body().string();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if ((weather != null && "ok".equals(weather.status)) || ("now".equals(cate))){
                            SharedPreferences.Editor editor = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                            Weather weather_new = Utility.handleWeatherResponse(responseText, weather, cate);
                            editor.putString(cate, responseText);
                            editor.apply();
                            switch (cate) {
                                case "now":
                                    requestWeather(weatherId, weather_new, "forecast");
                                    break;
                                case "forecast":
                                    requestWeather(weatherId, weather_new, "lifestyle");
                                    break;
                                case "lifestyle":
                                    assert weather_new != null;
                                    showWeatherInfo(weather_new);
                                    break;
                            }
                        }else {
                            Toast.makeText(WeatherActivity.this, "請求到的數據出錯", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        });
    }

    // 處理並展示實體類 Weather 的數據
    private void showWeatherInfo(Weather weather){
        loadBingPic();
        String cityName = weather.basic.cityName;
        String updateTime = weather.update.updateTime;
        String degree = weather.now.temperature + "℃";
        String weatherInfo = weather.now.info;

        titleCity.setText(cityName);
        titleUpdateTime.setText(updateTime);
        degreeText.setText(degree);
        weatherInfoText.setText(weatherInfo);
        forecastLayout.removeAllViews();
        for (Forecast.forecast forecast: weather.forecastList){
            View view= LayoutInflater.from(this).inflate(R.layout.forecast_item, forecastLayout, false);
            TextView dateText = view.findViewById(R.id.date_text);
            TextView infoText = view.findViewById(R.id.info_text);
            TextView maxText = view.findViewById(R.id.max_text);
            TextView minText = view.findViewById(R.id.min_text);
            dateText.setText(forecast.date);
            if (forecast.day.equals(forecast.night)){
                infoText.setText(forecast.day);
            }else {
                infoText.setText(String.format("%s轉%s", forecast.day, forecast.night));
            }
            maxText.setText(forecast.tmp_max);
            minText.setText(forecast.tmp_min);
            forecastLayout.addView(view);
        }
        if(weather.now != null){
            humText.setText(weather.now.humidity);
            windText.setText(weather.now.directionOfWind);
        }
        for(LifeStyle.lifestyle lifestyle: weather.lifestyleList){
            if ("comf".equals(lifestyle.type)){
                comfortText.setText(String.format("舒適度：%s", lifestyle.txt));
            }
            if ("drsg".equals(lifestyle.type)){
                drsgText.setText(String.format("穿衣指數：%s", lifestyle.txt));
            }
            if ("sport".equals(lifestyle.type)){
                sportText.setText(String.format("運動建議：%s", lifestyle.txt));
            }
        }
        weatherLayout.setVisibility(View.VISIBLE);
    }
}

3、狀態欄融合

public class WeatherActivity extends AppCompatActivity {
。。。。。。

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 背景和狀態欄融合
        if (Build.VERSION.SDK_INT >= 21){
            View decorView = getWindow().getDecorView();
            decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            getWindow().setStatusBarColor(Color.TRANSPARENT);
        }
        setContentView(R.layout.activity_weather);

4、狀態欄不融合，只透明

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
......

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:fitsSystemWindows="true">
            ......

5、展示

八、手動更新天氣

1、使用下拉控件

    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
        android:id="@+id/swipe_refresh"
        android:layout_height="match_parent"
        android:layout_width="match_parent">

        <ScrollView>
           ......
        </ScrollView>
    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

2、加入邏輯

public class WeatherActivity extends AppCompatActivity {
......

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 背景和狀態欄融合
        if (Build.VERSION.SDK_INT >= 21){
            View decorView = getWindow().getDecorView();
            decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            getWindow().setStatusBarColor(Color.TRANSPARENT);
        }
        setContentView(R.layout.activity_weather);
        swipeRefreshLayout = findViewById(R.id.swipe_refresh);
        swipeRefreshLayout.setColorSchemeResources(R.color.colorPrimary);

        // 初始化控件
        weatherLayout = findViewById(R.id.weather_layout);
        titleCity = findViewById(R.id.title_city);
        titleUpdateTime = findViewById(R.id.title_update_time);
        weatherInfoText = findViewById(R.id.weather_info_text);
        forecastLayout = findViewById(R.id.forecast_layout);
        humText = findViewById(R.id.hum_text);
        windText = findViewById(R.id.wind_text);
        comfortText = findViewById(R.id.comfort_text);
        drsgText = findViewById(R.id.drsg_text);
        sportText = findViewById(R.id.sport_text);
        degreeText = findViewById(R.id.degree_text);
        bingPicImg = findViewById(R.id.bing_pic_img);


        Weather weather = new Weather();
        SharedPreferences prefs = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE);
        String bingPic = prefs.getString("bing_pic", null);
        if(bingPic != null){
            Glide.with(this).load(bingPic).into(bingPicImg);
        }else {
            loadBingPic();
        }
        String nowString = prefs.getString("now", null);
        String forecastString = prefs.getString("forecast", null);
        String lifestyleString = prefs.getString("lifestyle", null);
        if(TextUtils.isEmpty(nowString) || TextUtils.isEmpty(forecastString) || TextUtils.isEmpty(lifestyleString)){
            // 無緩存時去服務器查詢天氣
            mWeatherId = getIntent().getStringExtra("weather_id");
            weatherLayout.setVisibility(View.INVISIBLE);
            requestWeather(mWeatherId, weather, "now");
        }else{
            // 有緩存時直接讀取數據
            weather = Utility.handleWeatherResponse(nowString, weather, "now");
            weather = Utility.handleWeatherResponse(forecastString, weather, "forecast");
            weather = Utility.handleWeatherResponse(lifestyleString, weather, "lifestyle");
            mWeatherId = weather.basic.weatherId;
            assert weather != null;
            showWeatherInfo(weather);
        }
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                requestWeather(mWeatherId, new Weather(), "now");
            }
        });
    }

    // 加載每日一圖
    private void loadBingPic() {
        String requestBingPic = "http://guolin.tech/api/bing_pic";
        HttpUtil.sendOkHttpRequest(requestBingPic, new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                Toast.makeText(WeatherActivity.this, "壁紙加載出錯", Toast.LENGTH_SHORT).show();
                e.printStackTrace();
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                final String bingPic = response.body().string();
                SharedPreferences.Editor editor = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                editor.putString("bing_pic", bingPic);
                editor.apply();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Glide.with(WeatherActivity.this).load(bingPic).into(bingPicImg);
                    }
                });
            }
        });
    }

    // 構造Url
    private String reUrl(String cate, String weatherId){
        String key = "cd9034ce70ad477b8454b6638261f0a5";
        return "https://free-api.heweather.net/s6/weather/" + cate + "?location=" + weatherId + "&key=" + key;
    }


    // 根據天氣 id 查詢城市天氣
    public void requestWeather(final String weatherId, final Weather weather,final String cate){
        String requestUrl = reUrl(cate, weatherId);
        Log.d("???", requestUrl);
        HttpUtil.sendOkHttpRequest(requestUrl, new Callback() {
            @Override
            public void onFailure(@NotNull final Call call, @NotNull IOException e) {
                e.printStackTrace();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        switch (cate) {
                            case "now":
                                Toast.makeText(WeatherActivity.this, "獲取今天天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "lifestyle":
                                Toast.makeText(WeatherActivity.this, "獲取生活指數失敗", Toast.LENGTH_SHORT).show();
                                break;
                            case "forecast":
                                Toast.makeText(WeatherActivity.this, "獲取預報天氣失敗", Toast.LENGTH_SHORT).show();
                                break;
                        }
                        swipeRefreshLayout.setRefreshing(false);
                    }
                });
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                final String responseText = response.body().string();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if ((weather != null && "ok".equals(weather.status)) || ("now".equals(cate))){
                            SharedPreferences.Editor editor = getApplicationContext().getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                            Weather weather_new = Utility.handleWeatherResponse(responseText, weather, cate);
                            editor.putString(cate, responseText);
                            editor.apply();
                            switch (cate) {
                                case "now":
                                    requestWeather(weatherId, weather_new, "forecast");
                                    break;
                                case "forecast":
                                    requestWeather(weatherId, weather_new, "lifestyle");
                                    break;
                                case "lifestyle":
                                    assert weather_new != null;
                                    showWeatherInfo(weather_new);
                                    mWeatherId = weather.basic.weatherId;
                                    swipeRefreshLayout.setRefreshing(false);
                                    break;
                            }
                        }else {
                            swipeRefreshLayout.setRefreshing(false);
                            Toast.makeText(WeatherActivity.this, "請求到的數據出錯", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
            }
        });
    }

    // 處理並展示實體類 Weather 的數據
    private void showWeatherInfo(Weather weather){
        loadBingPic();
        String cityName = weather.basic.cityName;
        String updateTime = weather.update.updateTime;
        String degree = weather.now.temperature + "℃";
        String weatherInfo = weather.now.info;

        titleCity.setText(cityName);
        titleUpdateTime.setText(updateTime);
        degreeText.setText(degree);
        weatherInfoText.setText(weatherInfo);
        forecastLayout.removeAllViews();
        for (Forecast.forecast forecast: weather.forecastList){
            View view= LayoutInflater.from(this).inflate(R.layout.forecast_item, forecastLayout, false);
            TextView dateText = view.findViewById(R.id.date_text);
            TextView infoText = view.findViewById(R.id.info_text);
            TextView maxText = view.findViewById(R.id.max_text);
            TextView minText = view.findViewById(R.id.min_text);
            dateText.setText(forecast.date);
            if (forecast.day.equals(forecast.night)){
                infoText.setText(forecast.day);
            }else {
                infoText.setText(String.format("%s轉%s", forecast.day, forecast.night));
            }
            maxText.setText(forecast.tmp_max);
            minText.setText(forecast.tmp_min);
            forecastLayout.addView(view);
        }
        if(weather.now != null){
            humText.setText(weather.now.humidity);
            windText.setText(weather.now.directionOfWind);
        }
        for(LifeStyle.lifestyle lifestyle: weather.lifestyleList){
            if ("comf".equals(lifestyle.type)){
                comfortText.setText(String.format("舒適度：%s", lifestyle.txt));
            }
            if ("drsg".equals(lifestyle.type)){
                drsgText.setText(String.format("穿衣指數：%s", lifestyle.txt));
            }
            if ("sport".equals(lifestyle.type)){
                sportText.setText(String.format("運動建議：%s", lifestyle.txt));
            }
        }
        weatherLayout.setVisibility(View.VISIBLE);
    }
}

3、展示

九、手動切換城市

1、導航按鈕

在屏幕左邊先加個按鈕：
title.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize">

    <Button
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_marginLeft="10dp"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:id="@+id/nav_button"
        android:background="@drawable/home"
        android:layout_alignParentStart="true"
        android:layout_marginStart="10dp" />
.........

2、滑動菜單

activity_weather.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
......

    <androidx.drawerlayout.widget.DrawerLayout
        android:id="@+id/drawer_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
            android:id="@+id/swipe_refresh"
            android:layout_height="match_parent"
            android:layout_width="match_parent">

            <ScrollView
......

                <LinearLayout
......

                </LinearLayout>

            </ScrollView>
        </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
        
        <fragment
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/choose_area_fragment"
            android:name="com.coolweather.android.ChooseAreaFragment"
            android:layout_gravity="start"/>
        
    </androidx.drawerlayout.widget.DrawerLayout>

</FrameLayout>

3、導航按鈕，滑動菜單聯結

public class WeatherActivity extends AppCompatActivity {
......
    public DrawerLayout drawerLayout;
    private Button navButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
......

        // 初始化控件
......
        drawerLayout = findViewById(R.id.drawer_layout);
        navButton = findViewById(R.id.nav_button);

        navButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                drawerLayout.openDrawer(GravityCompat.START);
            }
        });

4、邏輯處理

修改碎片ChooseAreaFragment:

......

	@Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if(currentLevel == LEVEL_PROVINCE){
                    selectedProvince = provinceList.get(position);
                    queryCities();
                }else if(currentLevel == LEVEL_CITY){
                    selectedCity = cityList.get(position);
                    queryCounties();
                }else if(currentLevel == LEVEL_COUNTY){
                    String weatherId = countyList.get(position).getWeatherId();
                    if(getActivity() instanceof MainActivity){
                        Intent intent = new Intent(getActivity(), WeatherActivity.class);
                        intent.putExtra("weather_id", weatherId);
                        startActivity(intent);
                        getActivity().finish();
                    }else if (getActivity() instanceof  WeatherActivity){
                        WeatherActivity activity = (WeatherActivity) getActivity();
                        activity.drawerLayout.closeDrawers();
                        activity.swipeRefreshLayout.setRefreshing(true);
                        activity.requestWeather(weatherId, new Weather(), "now");
                    }

                }
            }
        });

......

5、展示

十、後臺自動更新天氣

1、新建服務

新建一個服務AutoUpdateService：

ublic class AutoUpdateService extends Service {
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        updateWeather();
        updateBingPic();
        AlarmManager manager = (AlarmManager) getSystemService(ALARM_SERVICE);
        int anHour = 2 * 60 * 60 * 1000;    // 每兩小時更新一次
        long triggerAtTime = SystemClock.elapsedRealtime()+anHour;
        Intent i = new Intent(this, AutoUpdateService.class);
        PendingIntent pi = PendingIntent.getService(this, 0, i ,0);
        manager.cancel(pi);
        manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtTime, pi);
        return super.onStartCommand(intent, flags, startId);
    }

    private void updateWeather() {
        final SharedPreferences prefs = getSharedPreferences("weather_data", MODE_PRIVATE);
        String nowString = prefs.getString("now", null);
        if(nowString != null){
            String weatherId = Utility.handleWeatherResponse(nowString, new Weather(), "now").basic.weatherId;
            savedData(reUrl("now", weatherId), "now");
            savedData(reUrl("forecast", weatherId), "forecast");
            savedData(reUrl("lifestyle", weatherId), "lifestyle");
        }
    }
    // 存放數據
    private void savedData(String weatherUrl, final String cate){
        HttpUtil.sendOkHttpRequest(weatherUrl, new Callback() {
            @Override
            public void onFailure(@NotNull final Call call, @NotNull IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String responseText = response.body().string();
                SharedPreferences.Editor editor = getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                editor.putString(cate, responseText);
                editor.apply();
            }
        });
    }
    
    // 構造Url
    private String reUrl(String cate, String weatherId){
        String key = "cd9034ce70ad477b8454b6638261f0a5";
        return "https://free-api.heweather.net/s6/weather/" + cate + "?location=" + weatherId + "&key=" + key;
    }

    private void updateBingPic() {
        String requestBingPic = "http://guolin.tech/api/bing_pic";
        HttpUtil.sendOkHttpRequest(requestBingPic, new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String bingPic = response.body().string();
                SharedPreferences.Editor editor = getSharedPreferences("weather_data", MODE_PRIVATE).edit();
                editor.putString("bing_pic", bingPic);
                editor.apply();
            }
        });
    }
}

2、啓動服務

    // 處理並展示實體類 Weather 的數據
    private void showWeatherInfo(Weather weather){
    ......
        weatherLayout.setVisibility(View.VISIBLE);
        Intent intent = new Intent(this, AutoUpdateService.class);
        startService(intent);
    }

十一、修改圖標和名稱

1、修改圖標

修改<application>的屬性：

android:icon="@mipmap/logo"

然後將不同分辨率的logo.png放在所有的mipmap目錄下，圖標就修改好了

2、修改應用名

修改res/values/string.xml

<resources>
    <string name="app_name">酷歐天氣</string>
</resources>

即可

《第二行代碼》—— 酷歐天氣的開發

一、功能需求及技術可行性分析

1、具備的功能

2、技術可行性分析

二、正式編寫

一、基本配置

二、創建數據庫和表

1、添加依賴庫

2、設計數據庫表的結構

3、數據庫版本控制

三、遍歷全國省市縣數據

1、服務器交互

2、解析JSON

3、選擇地區的佈局

4、遍歷省市縣的碎片

5、佈局中引入碎片

6、聲明權限

7、展示

四、顯示天氣數據

1、基本格式

2、建立關係

五、編寫天氣界面

1、頭佈局

2、當前天氣佈局

3、未來天氣佈局

4、未來天氣子項佈局

5、空氣質量佈局

6、生活建議佈局

7、合併佈局

六、將天氣顯示到界面上

1、解析服務器JSON數據

2、在活動中處理數據

3、從省市縣列表跳轉到天氣頁面

4、選擇啓動頁面

5、展示

七、獲取必應天氣壁紙

1、天氣佈局修改

2、加載每日壁紙

3、狀態欄融合

4、狀態欄不融合，只透明

5、展示

八、手動更新天氣

1、使用下拉控件

2、加入邏輯

3、展示

九、手動切換城市

1、導航按鈕

2、滑動菜單

3、導航按鈕，滑動菜單 聯結

4、邏輯處理

5、展示

十、後臺自動更新天氣

1、新建服務

2、啓動服務

十一、修改圖標和名稱

1、修改圖標

2、修改應用名

3、導航按鈕，滑動菜單聯結