Android 按键事件小结

package xuyan.button;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.Toast;

public class ButtonOnKeyDownActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
    public boolean onKeyDown(int keyCode, KeyEvent event) 
    { 
        switch (keyCode) 
        { 
        case KeyEvent.KEYCODE_MENU: 
            Toast.makeText(getBaseContext(), 
                    "MENU was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break;   
            
        case KeyEvent.KEYCODE_BACK: 
            Toast.makeText(getBaseContext(), 
                    "返回键  was clicked", 
                    Toast.LENGTH_LONG).show(); 
            
            this.finish();
            break;  
            
        case KeyEvent.KEYCODE_DPAD_CENTER: 
            Toast.makeText(getBaseContext(), 
                    "Center was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break;                 
        case KeyEvent.KEYCODE_DPAD_LEFT: 
            Toast.makeText(getBaseContext(), 
                    "Left arrow was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break;                 
        case KeyEvent.KEYCODE_DPAD_RIGHT: 
            Toast.makeText(getBaseContext(), 
                    "Right arrow was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break;                 
        case KeyEvent.KEYCODE_DPAD_UP: 
            Toast.makeText(getBaseContext(), 
                    "Up arrow was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break; 
        case KeyEvent.KEYCODE_DPAD_DOWN: 
            Toast.makeText(getBaseContext(), 
                    "Down arrow was clicked", 
                    Toast.LENGTH_LONG).show(); 
            break;                 

        }
		return false;
        
    }

}