View

View中的setTag（Onbect）表示给View添加一个格外的数据，以后可以用getTag()将这个数据取出来。

可以用在多个Button添加一个监听器，每个Button都设置不同的setTag。这个监听器就通过getTag来分辨是哪个Button 被按下。

 

package fy.test; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button button1 = (Button) findViewById(R.id.Button01); Button button2 = (Button) findViewById(R.id.Button02); Button button3 = (Button) findViewById(R.id.Button03); Button button4 = (Button) findViewById(R.id.Button04); MyListener listener = new MyListener(); button1.setTag(1); button1.setOnClickListener(listener); button2.setTag(2); button2.setOnClickListener(listener); button3.setTag(3); button3.setOnClickListener(listener); button4.setTag(4); button4.setOnClickListener(listener); } public class MyListener implements View.OnClickListener { @Override public void onClick(View v) { int tag = (Integer) v.getTag(); switch (tag) { case 1: System.out.println("button1 click"); break; case 2: System.out.println("button2 click"); break; case 3: System.out.println("button3 click"); break; case 4: System.out.println("button4 click"); break; } } } }

main.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> <Button android:text="Button01" android:id="@+id/Button01" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> <Button android:text="Button02" android:id="@+id/Button02" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> <Button android:text="Button03" android:id="@+id/Button03" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> <Button android:text="Button04" android:id="@+id/Button04" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> </LinearLayout>