android button click事件

package a.a;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class AActivity extends Activity {
 /** Called when the activity is first created. */

 EditText Ev1;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);

  Ev1 = (EditText)findViewById(R.id.editText1); 

  //第一种方式 
  Button Btn1 = (Button)findViewById(R.id.button1);//获取按钮资源 
  Btn1.setOnClickListener(new Button.OnClickListener(){//创建监听 
   public void onClick(View v) { 
    String strTmp = "点击Button01"; 
    Ev1.setText(strTmp); 
   } 

  }); 

  //第二种方式 
  Button Btn2 = (Button) findViewById(R.id.button2);//获取按钮资源 
  Btn2.setOnClickListener(listener);//设置监听 

 }

 Button.OnClickListener listener = new Button.OnClickListener(){//创建监听对象 
  public void onClick(View v){ 
   String strTmp="点击Button02"; 
   Ev1.setText(strTmp); 
  } 

 };

 //第三种方式(Android1.6版本及以后的版本中提供了) 
 public void Btn3OnClick(View view){ 
  String strTmp="点击Button03";
  Ev1.setText(strTmp);

 } 
}