将UILongPressGestureRecognizer与UIPanGestureRecognizer组合在一起

Question

我喜欢将UILongPressGestureRecognizer与UIPanGestureRecognizer结合使用.

UIPanGestureRecognizer应该从长按开始.有一个简单的方法吗？还是我真的要写自己的手势识别器？

我不喜欢在主屏幕上.你按下一个图标,一段时间后图标开始摇晃.之后我没有从屏幕上松开手指,我可以开始拖动手指下的图标.

Answer 1

实际上,您不必组合手势识别器 - 您只能使用UILongPressGestureRecognizer执行此操作...一旦您的触摸在'allowableMovement'中保持'minimumPressDuration',您就进入StateBegan.只要你不抬起任何手指,你就会保持连续的longPressGesture - 所以你可以开始移动手指并通过StateChanged跟踪运动.

长按手势是连续的.当指定时间段(minimumPressDuration)按下允许的手指数(numberOfTouchesRequired)并且触摸不超出允许的移动范围(allowableMovement)时,手势开始(UIGestureRecognizerStateBegan).每当手指移动时,手势识别器转换到改变状态,并且当任何手指被抬起时,手势识别器结束(UIGestureRecognizerStateEnded).

Answer 2

我遇到这个问题有点困难.接受的答案还不够.无论我在该方法中使用什么,都会调用pan或longpress处理程序.我找到的解决方案如下:

1. 确保将手势识别器的委托分配到同一个类(在我的情况下为self)并确保委托类是a UIGestureRecognizerDelegate.

2. 将以下委托方法添加到您的类中(根据上面的答案):

   - (BOOL) gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer 
   shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer { 
        return YES;
   }
   

3. 将以下委托方法添加到您的类:

   - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
        if([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]] && ! shouldAllowPan) {
             return NO;
        }
        return YES;
   }
   

4. 然后添加一个属性或ivar,它将跟踪是否应该允许平底锅开始(参见上面的方法).就我而言BOOL shouldAllowPan.

5. 将BOOL设置为NO您的init或viewDidLoad.在你的longPress处理程序中设置BOOL为YES.我是这样做的:

   - (void) longPressHandler: (UILongPressGestureRecognizer *) gesture {
   
        if(UIGestureRecognizerStateBegan == gesture.state) {
           shouldAllowPan = NO;
        }
   
        if(UIGestureRecognizerStateChanged == gesture.state) {
           shouldAllowPan = YES;
        }
   }
   

6. 在panHandler中我检查BOOL:

   - (void)panHandler:(UIPanGestureRecognizer *)sender{
       if(shouldAllowPan) {
             // do your stuff
       }
   

7. 最后在panHandler中重置BOOL:

   else if(sender.state == UIGestureRecognizerStateEnded || sender.state == UIGestureRecognizerStateFailed || sender.state == UIGestureRecognizerStateCancelled) {
       shouldAllowPan = NO;
   }
   

8. 然后去喝啤酒祝贺自己.;)

Answer 3

我找到了一个解决方案:这个UIGestureRecognizerDelegate方法完全符合我的要求:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer 
shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer

Answer 4

Andy B在Swift中的方法,

1. 将UIGestureRecognizerDelegate委托添加到类中

   class ViewController: UIViewController, UIGestureRecognizerDelegate
   

2. 添加成员变量

   var shouldAllowPan: Bool = false
   

3. 添加手势并需要将平移手势委托添加到VC.这需要触发shouldRecognizeSimultaneouslyWithGestureRecognizer和gestureRecognizerShouldBegin函数

   // long press
   let longPressRec = UILongPressGestureRecognizer(target: self, action: "longPress:")
   yourView.addGestureRecognizer(longPressRec)
   
   // drag
   let panRec = UIPanGestureRecognizer(target: self, action: "draggedView:")
   panRec.delegate = self
   yourView.addGestureRecognizer(panRec)
   

4. 允许同时手势

   func gestureRecognizer(UIGestureRecognizer,
   shouldRecognizeSimultaneouslyWithGestureRecognizer:UIGestureRecognizer) -> Bool {
       // println("shouldRecognizeSimultaneouslyWithGestureRecognizer");
       return true
   }
   
   func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
        // We only allow the (drag) gesture to continue if it is within a long press
        if((gestureRecognizer is UIPanGestureRecognizer) && (shouldAllowPan == false)) {
            return false;
        }
        return true;
   }
   

5. 在长按处理机内:

   func longPress(sender: UILongPressGestureRecognizer) {
   
       if(sender.state == .Began) {
           // handle the long press
       }
       else if(sender.state == .Changed){
           shouldAllowPan = true
   
       }
       else if (sender.state == .Ended) {
           shouldAllowPan = false
       }
   }