ActivityにおけるonClickイベントの3つの書き方

 1 import android.app.Activity;
 2 import android.os.Bundle;
 3 import android.view.View;
 4 import android.widget.Button;
 5 import android.widget.EditText;
 6 
 7 
 8 public class activity extends Activity {
 9     /** Called when the activity is first created. */
10     EditText Ev1;
11     
12     @Override
13     public void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.main);
16 
17         Ev1 = (EditText)findViewById(R.id.EditText01);
18         // 
19         Button Btn1 = (Button)findViewById(R.id.Button01);// 
20         Btn1.setOnClickListener(new Button.OnClickListener(){// 
21             @Override
22             public void onClick(View v) {
23                 String strTmp = " Button01";
24                 Ev1.setText(strTmp);
25             }
26         });
27 
28         // 
29         Button Btn2 = (Button) findViewById(R.id.Button02);// 
30         Btn2.setOnClickListener(listener);// 
31     }
32    
33     Button.OnClickListener listener = new Button.OnClickListener(){// 
34         @Override
35         public void onClick(View v){
36             String strTmp=" Button02";
37             Ev1.setText(strTmp);
38         }
39     };
40     
41     // (Android1.6 )
42     public void Btn3OnClick(View view){
43         String strTmp=" Button03";
44         Ev1.setText(strTmp);
45     }
46 }