ImageButton的焦点和事件处理

Java代码 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.TextView; 
/**
 * ImageButton的焦点和事件处理
 *
 */ 
public class ActivityMain extends Activity { 
    private ImageButton myImageButton ; 
    private Button myButton; 
    private TextView myTextView; 
     
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main); 
         
        //创建三个组件 
        myImageButton = (ImageButton)findViewById(R.id.myImageButton); 
        myButton = (Button)findViewById(R.id.myButton); 
        myTextView = (TextView)findViewById(R.id.myTextView1); 
         
        //通过OnFocusChangeListener来响应ImageButton的onFocus事件 
        myImageButton.setOnFocusChangeListener(new ImageButton.OnFocusChangeListener() { 
            public void onFocusChange(View v, boolean hasFocus) { 
                //如果ImageButton得到焦点onFocus则改变ImageButton的图片 
                if(hasFocus==true) { 
                    //更改状态说明 
                    myTextView.setText("图片按钮状态为:Got Focus"); 
                    //更改按钮背景图片 
                    myImageButton.setImageResource(R.drawable.iconfull); 
                } else { 
                    myTextView.setText("图片按钮状态为: Lost Focus");