ios - 使用滑动手势快速更改 UISlider 值

Question

我有一个带有滑动手势的 UIView。

 let swipeUpGesture = UISwipeGestureRecognizer(target: self, action: #selector(NextStepCaptureVC.handleSwipeUp(gesture:)))
        swipeUpGesture.direction = .up
        view.addGestureRecognizer(swipeUpGesture)

func handleSwipeUp(gesture: UISwipeGestureRecognizer) {
        print("Swipe Up")
        heightSlider.setValue(20, animated: true)
    }

当我尝试更改值时，它起作用了，但值从 0 跳到 20。我希望值在滑动时不断变化。我该怎么做？

Answer 1

从您的代码来看，您似乎正试图将屏幕上的“上下平移”转化为 UISlider 值的变化。

正如其他人已经提到的，首先是将您的 UISwipeGestureRecognizer 更改为 UIPanGestureRecognizer

let pan = UIPanGestureRecognizer(target: self, action: #selector(pan(gesture:))) 
view.addGestureRecognizer(pan)

然后在平移函数中，您需要根据用户平移的程度更新 slider 值。

func pan(gesture: UIPanGestureRecognizer) {
    // The amount of movement up/down since last change in slider
    let yTranslation = gesture.translation(in: gesture.view).y

    // The slide distance needed to equal one value in the slider
    let tolerance: CGFloat = 5

    if abs(yTranslation) >= tolerance {
        let newValue = heightSlider.value + Float(yTranslation / tolerance)
        heightSlider.setValue(newValue, animated: true)

        // Reset the overall translation within the view
        gesture.setTranslation(.zero, in: gesture.view)
    }
}

只需调整 tolerance 变量即可让用户滑动更多/更少以调整 slider 值。