ios - 如何禁用 UIScrollView 到平移手势识别器？
<p><p>当平移手势识别器(我们称之为 <code>SomePanGestureRecognizer</code>)被调用时，如何禁用或强制使 <code>UIScrollView</code> 中的手势识别器失败？</p >
<p><code>gestureRecognizer(_:shouldBeRequiredToFailBy:)</code> 方法采用手势识别器参数，而不是平移手势识别器，我不知道这是我无法让它工作的原因还是因为我出现语法错误。</p>
<p>我有 <code>UIScrollView</code> 子类，用于强制失败的方法在下面的委托(delegate)中:</p>
<pre><code>class CustomScrollView: UIScrollView {
override init(frame: CGRect) {
super.init(frame: frame)
configure()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
configure()
}
private func configure() {
isScrollEnabled = true
showsHorizontalScrollIndicator = false
showsVerticalScrollIndicator = false
isPagingEnabled = true
bounces = false
alwaysBounceVertical = false
alwaysBounceHorizontal = false
}
}
// gesture recognizer delegate
extension CustomScrollView: UIGestureRecognizerDelegate {
// allow simultaneous gestures
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
// force failure
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
// TLDR: disable uiscrollview when SomePanGestureRecognizer is called
}
}
</code></pre>
<p><br/>
这是需要强制 <code>UIScrollView</code> 中的手势识别器失败的平移手势识别器:</p>
<pre><code>func addSomePanGestureRecognizer() {
SomePanGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(oneBPanGestureHandler(gesture:)))
oneBHandle.addGestureRecognizer(SomePanGestureRecognizer)
}
</code></pre>
<p><br/><br/>
<strong>更新</strong>我将 UIPanGestureRecognizer 子类化并使用同步委托(delegate)使其工作，但我担心这是一种不稳定的方法，因为我依赖 UIKit 在自定义平移手势之前始终禁用 UIScrollView .</p>
<pre><code>// gesture recognizer delegate
extension CustomScrollView: UIGestureRecognizerDelegate {
// simultaneous gestures
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if otherGestureRecognizer is CustomPanGestureRecognizer {
return false
} else {
return true
}
}
}
</code></pre>
<p><br/>
<strong>UPDATE 2</strong> 这也有效，但我不知道为什么，因为我觉得它不应该。不应该反过来吗？</p>
<pre><code>// force failure
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if otherGestureRecognizer is CustomPanGestureRecognizer {
return true
} else {
return false
}
}
</code></pre></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>我相信这就是您要找的:</p>
<pre><code>func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
let isPanAndOtherRecognizer = gestureRecognizer is UIPanGestureRecognizer && otherGestureRecognizer is SomePanGestureRecognizer
return !isPanAndOtherRecognizer
}
// force failure
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
let isPanAndOtherRecognizer = gestureRecognizer is UIPanGestureRecognizer && otherGestureRecognizer is SomePanGestureRecognizer
return isPanAndOtherRecognizer
}
</code></pre></p>
<p style="font-size: 20px;">关于ios - 如何禁用 UIScrollView 到平移手势识别器？，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/46008225/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/46008225/
</a>
</p>
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