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. */@Overridepublic 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 {@Overridepublic 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>