<activity
   android:name=".MainActivity"
   android:label="@string/app_name"
   android:launchMode="singleTop" >
   <intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
   </intent-filter>
</activity>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:orientation="vertical" >
 <Button
  android:id="@+id/myButton1"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="MyActivity1 Button" />
</LinearLayout>

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //打印當(dāng)前對(duì)象
  Log.d("MainActivity", this.toString());
  //去掉title
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.activity_main);
  //獲取button1
  Button button1 = (Button) findViewById(R.id.button1);
  //添加點(diǎn)擊事件
  button1.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View view) {
    //為了測(cè)試singleTop啟動(dòng)模式,當(dāng)點(diǎn)擊按鈕時(shí)，啟動(dòng)MyActivity1活動(dòng)
    Intent intent = new Intent(MainActivity.this,MyActivity1.class);
    //啟動(dòng)活動(dòng)
    startActivity(intent);
   }
  });
}

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //打印當(dāng)前對(duì)象
  Log.d("MyActivity1", this.toString());
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.activity1_my);
  //獲取按鈕
  Button myButton = (Button)findViewById(R.id.myButton1);
  //點(diǎn)擊事件
  myButton.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View arg0) {
    //啟動(dòng)MainActivity活動(dòng)
    Intent intent = new Intent(MyActivity1.this,MainActivity.class);
    startActivity(intent);
   }
  });
}