如何在Swift的滚动视图或Web视图中检测手指的位置？ （如果可能，使用touchesMoved）

Question

我想在Webview上打印用户手指的位置。

在网络视图上使用此功能（如下）无效

 override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let position = touch.location(in: self.view) // even when i replace this part with UIWebview
        print(position.x)
        print(position.y)
    }
}

Answer 1

我认为创建UIPanGestureRecognizer应该可以解决此问题，将以下代码添加到viewDidLoad()方法中：

override func viewDidLoad() {
    // ...

    let panGesture = UIPanGestureRecognizer(target: self, action: #selector(webViewtouchMoved(panGesture:)))
    panGesture.delegate = self

    webView.addGestureRecognizer(panGesture)

    // ...
}

webViewtouchMoved(panGesture:)方法：

func webViewtouchMoved(panGesture: UIPanGestureRecognizer) {
    if panGesture.state == .began || panGesture.state == .changed {
        let position = panGesture.location(in: view)
        print(position.x)
        print(position.y)
    }
}

另外，您应该为所需的ViewController添加此extension ：

// change 'ViewController' to your class name:
extension ViewController: UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
}

希望这对您有所帮助。