swift - 为什么我无法在操作函数中切换 UIGestureRecognizer 的属性

Question

我有两个 UITapGestureRecognizer 来处理单击和双击。我的代码是这样的:

let doubleTap = UITapGestureRecognizer(
    target: self, action: #selector(viewController.handleDouble)
)
doubleTap.numberOfTapsRequired = 2
myview.addGestureRecognizer(doubleTap)

let singleTap = UITapGestureRecognizer(
    target: self, action: #selector(viewController.handleSingle)
)
singleTap.numberOfTapsRequired = 1
singleTap.require(toFail: doubleTap)
myview.addGestureRecognizer(singleTap)

而handelDouble和handleSingle是处理双击和单击的函数。这非常有效。

现在我想创建一个 UITapGestureRecognizer 来处理这两种情况，例如:

let tap = UITapGestureRecognizer(
    target: self, action: #selector(viewController.handleTap(recognizer:))
)
myview.addGestureRecognizer(Tap)

在 handelTap 函数中我这样写:

func handleTap(recognizer: UITapGestureRecognizer) {
    switch recognizer.state {
    case .ended:
        if (recognizer.numberOfTapsRequired = 2) {
             // to do something with double tapping
        } else {
             // to do something with single tapping
        }
    default: break
    }
}

但是，这不起作用。更奇怪的是，当双击时，会发生单击的情况。

这也发生在 UISwipeGestureRecognizer 上，因为我无法使用一个函数来选择它的方向。

那么我们是否只能创建多个 UIGestureRecognizer 实例来完成这样的工作？

Answer 1

在您的代码中，singleTap 的 numberOfTapsRequired 等于 2。我认为正确的值是 1

let singleTap = UITapGestureRecognizer(
    target: self, action: #selector(viewController.handleSingle)
)
singleTap.numberOfTapsRequired = 2
singleTap.require(toFail: doubleTap)
myview.addGestureRecognizer(singleTap)