ios - 检测用户何时向左或向右滑动以在 WKWebView 上返回或返回

Question

我正在使用 WKWebView 并且我允许前后导航手势:

myWkWebView.allowsBackForwardNavigationGestures = true

现在，用户有两种返回方式:按下按钮或向左滑动。行为会有所不同，所以我想知道我如何才能知道用户何时刚刚向左/向右滑动，以便我可以处理这个问题。

我查看了 WKNavigationDelegate 引用资料 ( https://developer.apple.com/library/ios/documentation/WebKit/Reference/WKNavigationDelegate_Ref/ )，但找不到任何有用的东西。

有什么想法吗？

编辑

我忘了说我也尝试过添加滑动手势识别器，这样:

    let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(MyVC.respondToSwipeLeftOrRight(_:)))
    swipeRight.direction = UISwipeGestureRecognizerDirection.Right
    let swipeLeft = UISwipeGestureRecognizer(target: self, action: #selector(MyVC.respondToSwipeLeftOrRight(_:)))
    swipeLeft.direction = UISwipeGestureRecognizerDirection.Left
    self.view.addGestureRecognizer(swipeRight)
    self.view.addGestureRecognizer(swipeLeft)
    myWkWebView.scrollView.panGestureRecognizer.requireGestureRecognizerToFail(swipeRight)
    myWkWebView.scrollView.panGestureRecognizer.requireGestureRecognizerToFail(swipeLeft)

但每次我向左或向右滑动时它们都不会触发。

Answer 1

private var currentBackForwardItem: WKBackForwardListItem?
private func handleBackForwardWebView(navigationAction: WKNavigationAction) {
    if navigationAction.navigationType == .BackForward {
        let isBack = webView.backForwardList.backList
            .filter { $0 == currentBackForwardItem }
            .count == 0

        if isBack {

        } else {

        }
    }

    currentBackForwardItem = webView.backForwardList.currentItem
}

func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> Void) {
    handleBackForwardWebView(navigationAction)
    decisionHandler(.Allow)
}