Question

我是IOS的新人。在我的应用程序中，每次用户绘制圆圈时，我都会创建一个新的圆形子视图。在创建圆之后，我希望用户能够在父视图上拖动圆。如果用户创建了多个圆圈，我怎么知道触摸了哪个圆圈并在屏幕上拖动这个特定的圆圈。

Answer 1

我成功实现了我想要实现的目标。我在touchmoved circle中覆盖了subview方法，并在那里输入以下内容：

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *mytouch=[[touches allObjects] objectAtIndex:0];

    self.center = [mytouch locationInView:self.superview];

}

现在创建的每个circle，我都可以将其与屏幕一起拖动。

Answer 2

您可以将Pan手势添加到您想要移动的内容中：

// Add UIPanGestureRecognizer to each circle view u add and set a tag for each circle
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc]  initWithTarget: self   action: @selector(handlePan:)];
[view addGestureRecognizer:   panRecognizer];


-(void) handlePan: (UIGestureRecognizer *)sender
{
  UIPanGestureRecognizer *panRecognizer = (UIPanGestureRecognizer *)sender;
  UIView *view = sender.view;
// You can get to know which circle was moved by getting tag of this view
  if (panRecognizer.state == UIGestureRecognizerStateBegan ||
      panRecognizer.state ==  UIGestureRecognizerStateChanged)
  {
    CGPoint currentPoint = self.center;
    CGPoint translation =    [panRecognizer translationInView:     self.superView];
    view.center = CGPointMake(currentPoint.x + translation.x,  currentPoint.y + translation.y);
    [panRecognizer setTranslation: CGPointZero inView: self.view];
  }
}

IOS：在父视图上移动子视图

2 个答案: