如何防止意外触摸触发 swift 4.2 中的 touchesBegan？答案

【问题标题】：How to prevent that an accidental touch triggering the touchesBegan in swift 4.2?如何防止意外触摸触发 swift 4.2 中的 touchesBegan？
【发布时间】：2019-06-15 01:56:33
【问题描述】：

我有一个使用 touchesBegan 为用户执行操作的应用程序。但是，有时触摸屏幕只是留下一个文本字段。

有没有办法将 touchesBeagan 设置为仅在 2 或 3 秒后启动，同时保持触摸，如果触摸小于此值，则触发 resignFirstResponder，而不是触发动作？

为了帮助理解这里是我的触摸方法：

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    Feedback.share.hapticFeedback()
    startPoint = nil
    guard let touch = touches.first else {return}
    startPoint = touch.location(in: imageView)

    //Initialize whatever you need to begin showing selected rectangle below.
    rectShapeLayer.path = nil
    imageView.layer.addSublayer(rectShapeLayer)
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let touch = touches.first, let startPoint = startPoint else {return}
    let currentPoint: CGPoint
    if let predicted = event?.predictedTouches(for: touch), let lastPoint = predicted.last {
        currentPoint = lastPoint.location(in: imageView)
    } else {
        currentPoint = touch.location(in: imageView)
    }
    let frame = rect(from: startPoint, to: currentPoint)

    //Show bounding box
    rectShapeLayer.path = UIBezierPath(rect: frame).cgPath
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let touch = touches.first, let startPoint = startPoint else {return}
    let currentPoint = touch.location(in: imageView)
    let frame = rect(from: startPoint, to: currentPoint)

    //Remove bounding box but take snapshot of selected `CGRect` by frame
    rectShapeLayer.removeFromSuperlayer()
    let memeImage = imageView.snapshot(rect: frame, afterScreenUpdates: true)

    save(imageView: imageView, image: memeImage)

}

【问题讨论】：

标签： ios swift touches

【解决方案1】：

我找到了一种方法来保证屏幕上的触摸它只是执行 resignFirstResponder 而不是其他功能。

我只更改了 touchesEnded(_:) 方法，添加了“if frame.size.width

这对我来说效果很好。

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let touch = touches.first, let startPoint = startPoint else {return}
    let currentPoint = touch.location(in: ivPhoto)
    let frame = rect(from: startPoint, to: currentPoint)

    rectShapeLayer.removeFromSuperlayer()

    if frame.size.width < 1 {
        tfTop.resignFirstResponder()
        tfBottom.resignFirstResponder()
    } else {

        let memeImage = ivPhoto.snapshot(rect: frame, afterScreenUpdates: true)

        saveCrop(cropImage: memeImage)
    }
}

【讨论】：