屏蔽home鍵和返回鍵盤

//屏蔽返回鍵的代碼:  
public boolean onKeyDown(int keyCode,KeyEvent event) 
{ 
    switch(keyCode) 
    { 
        case KeyEvent.KEYCODE_HOME:return true; 
        case KeyEvent.KEYCODE_BACK:return true; 
        case KeyEvent.KEYCODE_CALL:return true; 
        case KeyEvent.KEYCODE_SYM: return true; 
        case KeyEvent.KEYCODE_VOLUME_DOWN: return true; 
        case KeyEvent.KEYCODE_VOLUME_UP: return true; 
        case KeyEvent.KEYCODE_STAR: return true; 
    } 
    return super.onKeyDown(keyCode, event); 
}

//屏蔽home鍵的代碼:  
public void onAttachedToWindow()  
{ 
    this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD); 
    super.onAttachedToWindow(); 
}