android onKeydown

package wyf.ytl;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.Button;
public class Sample_7_1 extends Activity {
        public final String TAG = "Sample_7_1";
        MyButton myButton;
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);  

        myButton = new MyButton(this);
        myButton.setText("全屏按钮");
        myButton.setTextSize();
        setContentView(myButton);
    }
    public boolean onKeyDown(int keyCode, KeyEvent event)
    { //重写的键盘按下监听
        Log.d(TAG, "activity onKeyDown");
        return super.onKeyDown(keyCode, event);
    }
    class MyButton extends Button
    {
        public MyButton(Context context)
        {
            super(context);
        }
        public boolean onKeyDown(int keyCode, KeyEvent event)
        {//重写的键盘按下监听
            Log.d(TAG, "MyView onKeyDown");
            //打印日志
            return true;  //return false;
        }
    }
    }