android 中 Button 的监听事件的多种实现方式

public class MainActivity extends Activity {
private Button btn = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.btn = (Button) this.findViewById(R.id.btn);
this.btn.setOnClickListener(new MyOnclickBtn());
}

// 方式一 采用内部类
private class MyOnclickBtn implements OnClickListener {
@Override
public void onClick(View v) {

}
}

}

public class MainActivity extends Activity {
private Button btn = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.btn = (Button) this.findViewById(R.id.btn);
this.btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

}
});
}

}

public class MainActivity extends Activity implements OnClickListener {
private Button btn = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.btn = (Button) this.findViewById(R.id.btn);
this.btn.setOnClickListener(this);
}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

}

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical"
tools:context=".MainActivity" >

<Button
android:id="@+id/btn"

android:onClick="myBtnOnclick"

android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dip"
android:text="确定" />

</LinearLayout>

//代码这样调用：
public class MainActivity extends Activity {
private Button btn = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.btn = (Button) this.findViewById(R.id.btn);
}

public void myBtnOnclick(View view) {
//to do something
}

}
//关于第四方法中一定要保证.xml 文件中配置的方法名与代码中的方法名一致。