實驗目的
(1)掌握Activity回傳數據;
(2)android提供startActivityForResult()方法來回傳數據,第一個參數是intent,第二個參數是請求碼(判斷數據的來源);
示例代碼
//使用該方法啓動Main2Activity會在MainActivity頁面回調onActivityResult方法,
//所以在MainActivity頁面中重寫onActivityResult方法來獲取返回數據
Intent intent = new Intent(this,Main2Activity.class);
startActivityForResult(intent,1);
(3)setResult()方法接收兩個參數,第一個參數是結果碼(0或1),第二個參數是帶有數據的intent,回傳過去給執行startActivityForResult()方法的Activity;
示例代碼
Intent intent = new Intent();
intent.putExtra("equipment",itemInfo);//傳送金劍值保存到intent
//setResult方法的作用是讓當前Activity返回到它的調用者,這裏是讓Main2Acitivity返回到MainAcitivity
setResult(1,intent);
主要功能
實現數據的回傳功能
(1)打開app主界面,顯示如圖:
(2)點擊小寶寶購買裝備,顯示如圖:
(3)點擊這一視圖任意界面,跳轉爲原界面,數值改變,顯示如圖:
程序源代碼(有註釋)
(1)主界面的MainActivity
package com.myapplication;
import android.content.Intent;
import android.sax.StartElementListener;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
import cn.itcat.domain.ItemInfo;
public class MainActivity extends AppCompatActivity {
//定義進度條
private ProgressBar mProgressBar1;
private ProgressBar mProgressBar2;
private ProgressBar mProgressBar3;
//定義屬性值
private TextView mLifeTV;
private TextView mSpeedTV;
private TextView mAttackTV;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化,讓視圖上的TextView對應到MainAcitivity
mLifeTV = (TextView)findViewById(R.id.tv_life_progress);
mSpeedTV = (TextView)findViewById(R.id.tv_speed_progress);
mAttackTV = (TextView)findViewById(R.id.tv_attack_progress);
//初始化進度條
initProgress();
}
//進度條初始化
private void initProgress(){
//初始化,讓視圖上的進度條對應到MainAcitivity
mProgressBar1 = (ProgressBar)findViewById(R.id.progressBar1);
mProgressBar2 = (ProgressBar)findViewById(R.id.progressBar2);
mProgressBar3 = (ProgressBar)findViewById(R.id.progressBar3);
//設置最大值
mProgressBar1.setMax(1000);
mProgressBar2.setMax(1000);
mProgressBar3.setMax(1000);
}
//開啓新的activity,取得返回值
public void click(View view){
Intent intent = new Intent(this,Main2Activity.class);
//使用該方法啓動Main2Activity會在MainActivity頁面回調onActivityResult方法,
//所以在MainActivity頁面中重寫onActivityResult方法來獲取返回數據
startActivityForResult(intent,1);
}
//重寫onActivityResult方法如下
protected void onActivityResult(int requestCode,int resultCode,Intent data){
super.onActivityResult(requestCode,resultCode,data);
if(data!=null){
if(resultCode==1){
if(requestCode==1){
//得到在Main2Activity頁面傳入的值
ItemInfo info = (ItemInfo)data.getSerializableExtra("equipment");
updateProgress(info);
}
}
}
}
//更新進度條
private void updateProgress(ItemInfo info){
//得到進度條原來的值
int progress1 = mProgressBar1.getProgress();
int progress2 = mProgressBar2.getProgress();
int progress3 = mProgressBar3.getProgress();
//修改進度條的值(原來的+新增的值)
mProgressBar1.setProgress(progress1+info.getLife());
mProgressBar2.setProgress(progress2+info.getAttack());
mProgressBar3.setProgress(progress3+info.getSpeed());
//把值傳給view頁面
mLifeTV.setText(mProgressBar1.getProgress()+"");
mAttackTV.setText(mProgressBar2.getProgress()+"");
mSpeedTV.setText(mProgressBar3.getProgress()+"");
}
}
(2)主界面對應的xml文件
<?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="match_parent"
android:orientation="vertical"
android:gravity="center"
tools:context="com.myapplication.MainActivity">
<TableLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginBottom="20dp">
<TableRow
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="生命值:"
android:textColor="@android:color/black"
android:textSize = "14sp" />
<ProgressBar
android:id="@+id/progressBar1"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="2"/>
<TextView
android:id="@+id/tv_life_progress"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="0"
android:layout_gravity="center"
android:textColor="#000000"/>
</TableRow>
<TableRow
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="攻擊力:"
android:textColor="@android:color/black"
android:textSize = "14sp" />
<ProgressBar
android:id="@+id/progressBar2"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="2"/>
<TextView
android:id="@+id/tv_attack_progress"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="0"
android:layout_gravity="center"
android:textColor="#000000"/>
</TableRow>
<TableRow
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="敏捷:"
android:textColor="@android:color/black"
android:textSize = "14sp" />
<ProgressBar
android:id="@+id/progressBar3"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="2"/>
<TextView
android:id="@+id/tv_speed_progress"
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="0"
android:layout_gravity="center"
android:textColor="#000000"/>
</TableRow>
</TableLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="50dp"
android:layout_marginRight="50dp"
android:layout_marginTop="20dp">
<Button
android:id="@+id/btn_baby"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawablePadding="3dp"
android:drawableRight="@android:drawable/ic_menu_add"
android:onClick="click"
android:text="小寶寶購買裝備"
android:textSize="14sp"/>
</RelativeLayout>
</LinearLayout>
(3)遊戲裝備界面的Main2Acivit文件
package com.myapplication;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import cn.itcat.domain.ItemInfo;
//視圖監聽
public class Main2Activity extends AppCompatActivity implements View.OnClickListener {
private ItemInfo itemInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
//初始化一個武器
itemInfo = new ItemInfo("金劍",100,20,20);
//r1是視圖的id,這裏的意思是找到視圖的id,監聽視圖上的click
findViewById(R.id.r1).setOnClickListener(this);
//初始化
TextView mLifeTV = (TextView)findViewById(R.id.tv_life);//tv_life是Main2Activity中的id名賦值給mLifeTV
TextView mNameTV = (TextView)findViewById(R.id.tv_name);//tv_name是Main2Activity中的id名賦值給mNameTV
TextView mSpeedTV = (TextView)findViewById(R.id.tv_speed);//tv_speed是Main2Activity中的id名賦值給mSpeedTV
TextView mAttackTV = (TextView)findViewById(R.id.tv_attack);//tv_attack是Main2Activity中的id名賦值給mAttackTV
//TextView顯示字符串,傳入int編譯不會報錯,運行會報錯,
//設置金劍的屬性值
mLifeTV.setText("生命值+"+itemInfo.getLife());
mNameTV.setText(itemInfo.getName()+" ");
mSpeedTV.setText("敏捷度+"+itemInfo.getSpeed());
mAttackTV.setText("攻擊力+"+itemInfo.getAttack());
}
//如果這個界面上有click,觸發該函數
public void onClick(View view){
switch (view.getId()){//ri位Main2Activity整個視圖的屬性值
case R.id.r1:
Intent intent = new Intent();
intent.putExtra("equipment",itemInfo);//傳送金劍值保存到intent
//setResult方法的作用是讓當前Activity返回到它的調用者,這裏是讓Main2Acitivity返回到MainAcitivity
setResult(1,intent);
//銷燬Main2Activity
finish();
break;
}
}
}
(4)Main2Activity對應的xml文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/r1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.myapplication.Main2Activity">
<View
android:layout_width="30dp"
android:layout_height="30dp"
android:background="@android:drawable/ic_menu_info_details"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"/>
<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="60dp"
android:text = "商品名稱"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:orientation="vertical">
<TextView
android:id="@+id/tv_life"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="生命值"/>
<TextView
android:id="@+id/tv_attack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="攻擊力"/>
<TextView
android:id="@+id/tv_speed"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="速度"/>
</LinearLayout>
</RelativeLayout>