/**
	 * 屏蔽back键
	 */
	@Override
	public boolean dispatchKeyEvent(android.view.KeyEvent event) {
		 switch(event.getKeyCode())
		 {
		  case KeyEvent.KEYCODE_BACK:
		  
		   return false;
		 
		  
		 }
		 return true;
		};
		
		

android屏蔽back键