我想将UILongPressGestureRecognizer与UIPanGestureRecognizer结合使用。
UIPanGestureRecognizer应该从长按开始。有没有简单的方法可以做到这一点？还是我真的必须编写自己的手势识别器？
我不会在主屏幕上显示类似的内容。您按一个图标，一段时间后，图标开始摆动。之后，无需从屏幕上松开手指，我就可以开始在手指下面拖动图标。
实际上，您不必结合使用手势识别器-您可以仅使用UILongPressGestureRecognizer来完成此操作……只要您的触摸停留在'allowableMovement'中，并且输入'minimumPressDuration'，就可以输入StateBegan。只要您不抬起任何手指，就可以保持连续的longPressGesture状态-这样就可以开始移动手指并通过StateChanged跟踪移动。
长按手势是连续的。当在指定的时间段内（minimumPressDuration）按下了允许的手指数（numberOfTouchesRequired），并且触摸未超出允许的移动范围（allowableMovement）时，手势开始（UIGestureRecognizerStateBegan）。每当手指移动时，手势识别器都会转换为“更改”状态，并且在任何手指抬起时手势识别器都会终止（UIGestureRecognizerStateEnded）。
我在解决这个问题上有些困难。接受的答案还不够。无论我在该方法中使用什么方法，都会调用pan或longpress处理程序。我发现的解决方案如下：
UIGestureRecognizerDelegate。将以下委托方法添加到您的类中（按照上面的答案）：
- (BOOL) gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
将以下委托方法添加到您的类中：
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
if([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]] && ! shouldAllowPan) {
return NO;
}
return YES;
}
然后添加一个属性或ivar，它将跟踪是否应允许平移开始（请参见上面的方法）。就我而言BOOL shouldAllowPan。
在NO或init中将BOOL设置为viewDidLoad。在longPress处理程序内部，将BOOL设置为YES。我是这样的：
- (void) longPressHandler: (UILongPressGestureRecognizer *) gesture {
if(UIGestureRecognizerStateBegan == gesture.state) {
shouldAllowPan = NO;
}
if(UIGestureRecognizerStateChanged == gesture.state) {
shouldAllowPan = YES;
}
}
在panHandler里面，我在BOOL上进行了检查：
- (void)panHandler:(UIPanGestureRecognizer *)sender{
if(shouldAllowPan) {
// do your stuff
}
最后在panHandler中重置BOOL：
else if(sender.state == UIGestureRecognizerStateEnded || sender.state == UIGestureRecognizerStateFailed || sender.state == UIGestureRecognizerStateCancelled) {
shouldAllowPan = NO;
}
然后去喝啤酒祝贺自己。 ;）
我找到了解决方案：这个UIGestureRecognizerDelegate方法完全符合我的期望：
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
Andy B在Swift中的方法，
将UIGestureRecognizerDelegate委托添加到类中
class ViewController: UIViewController, UIGestureRecognizerDelegate
添加成员变量
var shouldAllowPan: Bool = false
添加手势，需要将平移手势委托添加到VC。需要此操作来触发shouldRecognizeWithGestureRecognizer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)
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;
}
在长按处理程序内：
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
}
}
在以下位置阅读Apple的UIGestureRecognizer类参考的“子类注释”部分：
用于组合更多手势：
var shouldAllowSecondGesture : Bool = false创建两个识别器
让longPressRec = UILongPressGestureRecognizer（目标：自我，动作：#selector（self.startDrag（sender :)））cell.addGestureRecognizer（longPressRec）让panGestureRecognizer = UIPanGestureRecognizer（目标：自我，行动：#selector（self.handlePan（sender :)））cell.isUserInteractionEnabled = truecell.addGestureRecognizer（panGestureRecognizer）
扩展您的VC并实现GestureRecognizerDelegate以实现此方法。
扩展名YourViewController：UIGestureRecognizerDelegate {
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
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
}
@objc func startDrag(sender:UIPanGestureRecognizer) {
if(sender.state == .began) {
// handle the long press
}
else if(sender.state == .changed){
shouldAllowPan = true
}
else if (sender.state == .ended) {
shouldAllowPan = false
}
}