在MainActivity中

 

public class MainActivity extends Activity implements OnClickListener{

 TextView tv; Button bt1,bt2,bt3; @Override protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);    tv = (TextView) findViewById(R.id.tv);  bt1=(Button) findViewById(R.id.bt1);  bt2=(Button) findViewById(R.id.bt2);  bt3=(Button) findViewById(R.id.bt3);    //内部类实现  bt1.setOnClickListener(new OnClickListener() {       @Override   public void onClick(View v) {     // TODO Auto-generated method stub    tv.setText("我是按钮1");   }  });    //主类继承  bt2.setOnClickListener(this);    bt3.setOnClickListener(new MyOnclickListener()); } //1.自定义类 class MyOnclickListener implements OnClickListener {

  @Override

  public void onClick(View v) {    // TODO Auto-generated method stub   tv.setText("我是按钮3");  }   }   //在布局文件中定义 public void onClick4(View v) {   tv.setText("我是按钮4"); }

 

 

 @Override

 public void onClick(View v) {   // TODO Auto-generated method stub  tv.setText("我是按钮2"); }

 

布局文件xml中

 

<LinearLayout xmlns:android=""

    xmlns:tools=""    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <TextView

        android:id="@+id/tv"        android:layout_width="fill_parent"        android:layout_height="200dp"        android:gravity="center"        android:text="@string/hello_world" />

    <Button

        android:id="@+id/bt1"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_below="@id/tv"        android:text="按钮1" />

    <Button

        android:id="@+id/bt2"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_below="@id/bt1"        android:text="按钮2" />

    <Button

        android:id="@+id/bt3"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_below="@id/bt2"        android:text="按钮3" />

    <Button

        android:onClick="onClick4"        android:id="@+id/bt4"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_below="@id/bt3"        android:text="按钮4" />

</RelativeLayout>