ios - 手指松开事件

Question

我在 Storyboard 中的 UIViewcontroller 上有 5 张图片。可以用手指在屏幕上移动五幅图像中的四幅(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图像(最终图形)上，标签上会出现“文本”。在我的声明中，我写了拦截。唯一的问题是标签上的文本在两个图像截断后立即出现。但我想让它在用户移开手指“放下”图像时出现。我该怎么做？

代码如下:

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

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

   if ([touch view] == graph1) {
      CGPoint location = [touch locationInView:self.view];
      graph1.center = location;
      [self interceptofgraphs]; 
   }

   if ([touch view] == graph2) {
      CGPoint location = [touch locationInView:self.view];
      graph2.center = location;
     [self interceptofgraphs];
   }

   if ([touch view] == graph3) {
      CGPoint location = [touch locationInView:self.view];
      graph3.center = location;
      [self interceptofgraphs];
   }

   if ([touch view] == graph4) {
      CGPoint location = [touch locationInView:self.view];
      graph4.center = location;
      [self interceptofgraphs];
   }
}

-(void)interceptofgraphs {

   if (CGRectIntersectsRect(graph2.frame, finalgraph.frame))
      graphlabel.text = [NSString stringWithFormat: @"Right answer. Well done!!"];

   if (CGRectIntersectsRect(graph1.frame, finalgraph.frame))
      graphlabel.text = [NSString stringWithFormat: @"Wrong!! not at all."];

   if (CGRectIntersectsRect(graph3.frame, finalgraph.frame))
      graphlabel.text = [NSString stringWithFormat: @"Wrong!! Try again"];

   if (CGRectIntersectsRect(graph4.frame, finalgraph.frame))
       graphlabel.text = [NSString stringWithFormat: @"Wrong!! NO"];
}

感谢所有回答的人!!

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];
}