Question

当我拖动手指时，我将如何进行触摸移动寻找距离。假设我的手指从A点开始，然后转到B点，这是10个像素，然后返回到A点，它们一起是20个像素。我该如何计算？

Answer 1

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
 UITouch *touch=[touches anyObject];
point1 = [touch locationInView:self];//(point2 is type of CGPoint)
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
 UITouch *touch=[touches anyObject];
point2 = [touch locationInView:self];//(point2 is type of CGPoint)
}

在CGPOint x或y轴的差异之后，你可以得到差异

Answer 2

Swift中的整体解决方案：

var startLocation: CGPoint?
var totalDistance: CGFloat = 0

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
    super.touchesBegan(touches, with: event)
    if let touch = touches.first {
        totalDistance = 0
        startLocation = touch.location(in: view)
    }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
    super.touchesMoved(touches, with: event)
    if let startLocation = startLocation, let touch = touches.first {
        let currentLocation = touch.location(in: view)
        let dX = currentLocation.x - startLocation.x
        let dY = currentLocation.y - startLocation.y
        self.totalDistance += sqrt(pow(dX, 2) + pow(dY, 2))
        self.startLocation = currentLocation
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
    super.touchesEnded(touches, with: event)
    print("Total distance: \(totalDistance)")
}

Answer 3

您可以跟踪用户已移动的点。请记住touchesBegin:中的点，在touchesMoved:中累积距离，并在touchesEnded:中获得整个距离。

– touchesBegan:withEvent:
– touchesMoved:withEvent:
- touchesEnded:withEvent:

Answer 4

为您的需求系统提供主要3委托方法从设备屏幕获取触摸点这三种方法是..

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@\"touchesBegan\");// here you can find out A point which user began to touch screen
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@\"touchesMoved\");// here get points of user move finger on screen to start to end point
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@\"touchesEnded\");// here user end touch or remove finger from Device Screen means  (B)
}

我希望这对你有用......

Answer 5

到目前为止，所有答案都不考虑多点触控。如果您需要记住哪个手指对应哪个拖动以支持多点触控，那么这些解决方案会变得有点困难。

如果您只对deltas感兴趣，比如说，您使用两根手指同时滚动两个不同的东西，则可以直接从touchesMoved中的触摸对象计算delta，并忘记记住任何状态在touchesBegan，

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for t in touches {
        let a = t.location(in: view)
        let b = t.previousLocation(in: view)
        let delta = b.y - a.y
        doSomethingWithDelta()
    }
}

例如，如果您想要上下移动一系列SKNode，

let nodesForFirstFinger = children.filter { $0.name == "firstGuys" }
let _ = nodesForFistFinger.map { $0.position.y += delta }

接触移动，计算距离

5 个答案: