Android代码学习-嵌套类，嵌套接口，匿名类，接口引用，子类调用父类的方法

public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
private Button.OnClickListener button_listener = new Button.OnClickListener() {
public void onClick(View v) {
setTitle("哎呦,button被点了一下");
}
};
}

button_listener是接口类型的对象引用，new 接口名{}，先实现接口，再产生一个匿名类，OnClickListener是Button的嵌套接口，类似嵌套类(Nested Class)，是Button的成员

java.lang.Object
android.view.View
android.widget.TextView
android.widget.Button

android.app.Activity:	protected void onCreate(Bundle savedInstanceState)

public void setContentView(int layoutResID)

public View findViewById(int id)

protected void onSaveInstanceState(Bundle outState)

public void setTitle(int titleId)

public void setTitle(CharSequence title)

public void startActivity(Intent intent)

android.view.View: 	public void setOnClickListener(View.OnClickListener l)

public interface OnClickListener

android.widget.Button:	void setOnClickListener(View.OnClickListener l)

interface	View.OnClickListener

android.view.View.OnClickListener:	abstract void	onClick(View v)