在swift中使用UIPanGestureRecognizer重载gestureRecognizerShouldBegin

Question

我有一个平移手势，我需要检查手势何时开始。在objective-C中，您可以使用

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer

可以使用UIPanGestureRecognizer重载

- (BOOL)gestureRecognizerShouldBegin:(UIPanGestureRecognizer *)gestureRecognizer

但快速

override func gestureRecognizerShouldBegin(gestureRecognizer: UIPanGestureRecognizer) -> Bool {

它不起作用并返回

使用选择器覆盖方法＆＃39; gestureRecognizerShouldBegin：＆＃39;具有不兼容的类型＆＃39;（UIPanGestureRecognizer） - ＆gt;布尔＆＃39;

如何在swift中重载此方法？

Answer 1

您不需要重载该方法，您可以改为：

override func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
    if let panGesture = gestureRecognizer as? UIPanGestureRecognizer {
        return ...
    }
    else {
        return ...
    }
}

Answer 2

删除覆盖，不要忘记添加UIGestureRecognizerDelegate扩展程序。

您可以在课程底部添加

class YourViewController: UIViewController {
    // You class declaration
}

extension YourViewController: UIGestureRecognizerDelegate {
    func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool {
        //
        return true
    }
}