target action

//為目前視圖指定當視圖接收到響應事件之後,由target來通過action方法進行響應.

- (void)addTarget:(id)target action:(SEL)action forControlEvents:(UIControlEvents)controlEvents

{

    //用執行個體變量存儲外界傳入的參數,友善在其他方法中使用

    _target = target;

    _action = action;

    _controlEvents = controlEvents;

    NSLog(@"%@",_target);

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

    if(UIControlEventTouchDown == _controlEvents)

    {

    //當目前視圖接收到觸摸事件之後,交由target去處理.

    [_target performSelector:_action withObject:self];

    }

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

    if (UIControlEventTouchUpInside == _controlEvents) {

        [_target performSelector:_action withObject:self];