當手指正在被它拖動時，改變UIButton的大小/當它被拖動時

Question

我有一個可拖動的UIButton。我希望它在被拖動或觸摸時具有不同的背景圖像。我想使用的圖像是正常尺寸的兩倍。我試過正常的：

[button setBackgroundImage:buttonHighlightedImage forState:UIControlStateHighlighted]; 

但這並不起作用。任何想法或提示將不勝感激。

Answer 1

如何：

  [button addTarget:self action:@selector(btnTouch:) 
    forControlEvents:UIControlEventTouchDown]; 
      [button addTarget:self action:@selector(btnTouchCancel:) 
    forControlEvents:UIControlEventTouchCancel]; 

      -(void)btnTouch:(id)sender{ 
       UIButton *button=sender; 
       [button setBackgroundImage:buttonHighlightedImage forState:UIControlStateNormal]; 
      } 

      -(void)btnTouchCancel:(id)sender{ 
       UIButton *button=sender; 
       [button setBackgroundImage:buttonNormalImage forState:UIControlStateNormal]; 
      }