Android菜鳥練習第八課 通過afinal更新apk

準備工作

1.將下載的afinal庫放到項目中

2.通過獲取當前應用版本號與接口提供的版本號進行比對，如當前版本號小於接口所提供版本號則進行更新apk操作，獲取應用當前版本號代碼如下

private int getVersionCode() {
    int code = 0;
    try {
    // 獲取packagemanager的實例
    PackageManager packageManager = getPackageManager();
    // getPackageName()是你當前類的包名，0代表是獲取版本信息
    PackageInfo packInfo = null;
        packInfo = packageManager.getPackageInfo(getPackageName(), 0);
         code = packInfo.versionCode;
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
    }

    return code;
}

第一部分  activity部分

public class MainActivity extends Activity {
    FinalHttp fh;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_update).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                update();                
            }
        });

    }

    public void update() {
        //apk安裝路徑
        String apkPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/qq.apk";
        //判斷安裝路徑是否存在同名APK,若存在則刪除該APK
        File f = new File(apkPath);
        if (f.exists()) {
            f.delete();
        }
        fh = new FinalHttp();
        //第一個參數爲文件下載地址 第二個參數爲APK安裝路徑
        fh.download("http://gdown.baidu.com/data/wisegame/4ae6d2d7378e6cdf/QQ_122.apk", apkPath,
                new AjaxCallBack<File>() {
                    @Override
                    public void onStart() {
                        super.onStart();
                        Toast.makeText(getApplicationContext(), "開始下載", Toast.LENGTH_SHORT).show();
                    }

                    //count爲下載文件的總長度,current爲當前下載的長度
                    @Override
                    public void onLoading(long count, long current) {
                        super.onLoading(count, current);
                        int progress = 0;
                        if (current != count && current != 0) {
                            progress = (int) (current / (float) count * 100);
                        } else {
                            progress = 100;
                        }
                    }

                    @Override
                    public void onSuccess(File t) {
                        super.onSuccess(t);
                        Toast.makeText(getApplicationContext(), "下載完成", Toast.LENGTH_SHORT).show();
                        installApk(t);
                    }

                    @Override
                    public void onFailure(Throwable t, int errorNo, String strMsg) {
                        super.onFailure(t, errorNo, strMsg);
                        Toast.makeText(getApplicationContext(), "下載失敗", Toast.LENGTH_SHORT).show();
                    }
                });
    }

    //安裝APK的方法
    private void installApk(File t) {
        Toast.makeText(MainActivity.this, t.exists() + "", Toast.LENGTH_SHORT).show();
        Intent intent = new Intent();
        intent.setAction("android.intent.action.VIEW");
        intent.addCategory("android.intent.category.DEFAULT");
        intent.setDataAndType(Uri.fromFile(t),
                "application/vnd.android.package-archive");
        startActivity(intent);
    }
}

第二部分 佈局中的部分

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

    <Button
        android:id="@+id/btn_update"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="update APK!" />
</RelativeLayout>

第三部分 配置文件部分

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.liying.downloadtest">

    <!--請求網絡權限和SD卡讀寫權限-->
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>