pressGestureRecognizer和touchesBegan

Question

我有以下问题。 我使用UILongPressGestureRecognizer将UIView置于“切换模式”。如果UIView处于“切换模式”，则用户可以在屏幕上拖动UIView。为了在屏幕上拖动UIView，我使用方法touchesBegan，touchesMoved和touchesEnded。

它有效，但是：我必须抬起手指才能拖动它，因为touchesBegan方法已被调用，因此不会再次调用，因此我无法拖动UIView屏幕周围。

触发touchesBegan后，是否有办法手动调用UILongPressGestureRecognizer UILongPressGestureRecognizer更改BOOL值，touchesBegan仅在此BOOL设置为YES时才有效

Answer 1

UILongPressGestureRecognizer是一个连续的手势识别器，所以不要诉诸touchesMoved或UIPanGestureRecognizer，只需检查UIGestureRecognizerStateChanged，例如：

- (void)viewDidLoad
{
    [super viewDidLoad];

    UILongPressGestureRecognizer *gesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
    [self.view addGestureRecognizer:gesture];
}

- (void)handleGesture:(UILongPressGestureRecognizer *)gesture
{
    CGPoint location = [gesture locationInView:gesture.view];

    if (gesture.state == UIGestureRecognizerStateBegan)
    {
        // user held down their finger on the screen

        // gesture started, entering the "toggle mode"
    }
    else if (gesture.state == UIGestureRecognizerStateChanged)
    {
        // user did not lift finger, but now proceeded to move finger

        // do here whatever you wanted to do in the touchesMoved
    }
    else if (gesture.state == UIGestureRecognizerStateEnded)
    {
        // user lifted their finger

        // all done, leaving the "toggle mode"
    }
}

Answer 2

我建议您使用UIPanGestureRecognizer作为推荐的拖动手势。

1. 您可以配置分钟。最多使用以下属性进行平移所需的触摸次数：

   <强> maximumNumberOfTouches

   <强> minimumNumberOfTouches

2. 您可以处理Began，Changed和Ended等状态，例如为所需状态设置动画。

3. 使用以下方法将该点转换为您想要的UIView。

   - (void)setTranslation:(CGPoint)translation inView:(UIView *)view

   示例：

   1. 您必须使用全局变量来保留旧框架。在UIGestureRecognizerStateBegan中获取此信息。

   2. 当状态为UIGestureRecognizerStateChanged时。您可以使用

   -(void) pannningMyView:(UIPanGestureRecognizer*) panGesture{
   
      if(panGesture.state==UIGestureRecognizerStateBegan){
        //retain the original state
      }else if(panGesture.state==UIGestureRecognizerStateChanged){
      CGPoint translatedPoint=[panGesture translationInView:self.view];
     //here you manage to get your new drag points.
     }
    }
   

   3. 阻力的速度。根据速度，您可以提供动画来显示UIView的弹跳

      - (CGPoint)velocityInView:(UIView *)view