是否有办法获得滑动手势或触摸的长度以便我可以计算距离?
问问题
33273 次
6 回答
56
从滑动手势中获取距离是不可能的,因为 SwipeGesture 会在手势结束时触发您可以准确访问该位置的方法一次。
也许您想使用 UIPanGestureRecognizer。
如果您可以使用平移手势,您将保存平移的起点,如果平移已结束,则计算距离。
- (void)panGesture:(UIPanGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateBegan) {
startLocation = [sender locationInView:self.view];
}
else if (sender.state == UIGestureRecognizerStateEnded) {
CGPoint stopLocation = [sender locationInView:self.view];
CGFloat dx = stopLocation.x - startLocation.x;
CGFloat dy = stopLocation.y - startLocation.y;
CGFloat distance = sqrt(dx*dx + dy*dy );
NSLog(@"Distance: %f", distance);
}
}
于 2011-01-28T14:32:03.667 回答
16
在斯威夫特
override func viewDidLoad() {
super.viewDidLoad()
// add your pan recognizer to your desired view
let panRecognizer = UIPanGestureRecognizer(target: self, action: #selector(panedView))
self.view.addGestureRecognizer(panRecognizer)
}
@objc func panedView(sender:UIPanGestureRecognizer){
var startLocation = CGPoint()
//UIGestureRecognizerState has been renamed to UIGestureRecognizer.State in Swift 4
if (sender.state == UIGestureRecognizer.State.began) {
startLocation = sender.location(in: self.view)
}
else if (sender.state == UIGestureRecognizer.State.ended) {
let stopLocation = sender.location(in: self.view)
let dx = stopLocation.x - startLocation.x;
let dy = stopLocation.y - startLocation.y;
let distance = sqrt(dx*dx + dy*dy );
NSLog("Distance: %f", distance);
if distance > 400 {
//do what you want to do
}
}
}
希望对所有 Swift 开拓者有所帮助
于 2015-11-03T18:34:07.743 回答
3
对于我们这些使用 Xamarin 的人:
void panGesture(UIPanGestureRecognizer gestureRecognizer) {
if (gestureRecognizer.State == UIGestureRecognizerState.Began) {
startLocation = gestureRecognizer.TranslationInView (view)
} else if (gestureRecognizer.State == UIGestureRecognizerState.Ended) {
PointF stopLocation = gestureRecognizer.TranslationInView (view);
float dX = stopLocation.X - startLocation.X;
float dY = stopLocation.Y - startLocation.Y;
float distance = Math.Sqrt(dX * dX + dY * dY);
System.Console.WriteLine("Distance: {0}", distance);
}
}
于 2014-04-29T21:55:19.683 回答
3
func swipeAction(gesture: UIPanGestureRecognizer) {
let transition = sqrt(pow(gesture.translation(in: view).x, 2)
+ pow(gesture.translation(in: view).y, 2))
}
于 2017-08-25T11:08:21.927 回答
2
您只能以标准方式进行:记住 touchBegin 的触摸点并比较 touchEnd 的点。
于 2011-01-28T14:28:31.470 回答
0
我有一个类似于 swift 中的答案的实现,它可以区分拖动和滑动,计算相对于容器的距离和滑动的速度。
@objc private func handleSwipe(sender: UIPanGestureRecognizer) {
if (sender.state == .began) {
self.swipeStart.location = sender.location(in: self)
self.swipeStart.time = Date()
}
else if (sender.state == .ended) {
let swipeStopLocation : CGPoint = sender.location(in: self)
let dx : CGFloat = swipeStopLocation.x - swipeStart.location.x
let dy : CGFloat = swipeStopLocation.y - swipeStart.location.y
let distance : CGFloat = sqrt(dx*dx + dy*dy );
let speed : CGFloat = distance / CGFloat(Date().timeIntervalSince(self.swipeStart.time))
let portraitWidth = min(self.frame.size.width, self.frame.size.height)
print("Distance: \(distance), speed: \(speed), dy: \(dy), dx: \(dx), portraitWidth: \(portraitWidth), c1: \(distance > portraitWidth * 0.4), c2: \(abs(dy) < abs(dx) * 0.25), c3: \(speed > portraitWidth * 3.0) ")
if distance > portraitWidth * 0.4 && abs(dy) < abs(dx) * 0.25 && speed > portraitWidth * 3.0 {
if dx > 0 {
delegate?.previousAssetPressed(self)
}else{
delegate?.nextAssetPressed(self)
}
}
}
}
于 2019-02-05T20:09:00.607 回答