手指释放事件

Question

我在UIViewcontroller的{​​{1}}上有5张图片。可以用手指在屏幕上移动五个图像中的4个（图1,2,3,4）。然后我创建了一个if语句：如果我将其中一个图像拖到固定的图像上（最终图形），标签上会出现“文本”。在我的发言中，我写了拦截。唯一的问题是，一旦两个图像截取，标签上的文字就会出现。但我想让用户移开手指以“放下”图像时显示。我怎么能这样做？

以下是代码：

Storyboard

感谢所有回答!!

Answer 1

这应该有效：

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

  UITouch *touch = [[event allTouches] anyObject];

  //we'll almost certainly need a location of touch
  CGPoint location = [touch locationInView:self.view];

  //we store the reference of a view that was touched into touchedView
  UIView *touchedView = [touch view];

  //if view that was touched is one of the views we're interested in
  if ((touchedView == graph1)||(touchedView == graph2)||
      (touchedView == graph3)||(touchedView == graph4)) {

    //we move it's center
    //since the touchedView hold's a reference to the view that
    //was touched - we're moving the right view for sure
    touchedView.center = location;    
  }
}

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

  //we only want to check whitch view was moved at the end 
  //when user releases the touch
  [self interceptofgraphs];
}