升级到 Swift 3.0 后从左到右的动画不起作用答案

【问题标题】：Left to right animation not working after upgrade to Swift 3.0升级到 Swift 3.0 后从左到右的动画不起作用
【发布时间】：2016-10-07 20:33:36
【问题描述】：

所以我刚刚从 2.3 升级到 Swift 3.0。除了这行代码及其错误之外，关于我的项目的其他一切都很好：

        if let delegate: AnyObject = completionDelegate {
        leftToRightTransition.delegate = delegate //ERROR MESSAGE
    }

错误信息说：

无法将“AnyObject”类型的值赋给 CAAnimation 类型

下面是完整的相关代码块。本质上，这段代码就是动画。在我的项目的其他地方（我很肯定这与问题无关，而只是为了上下文）有代码允许用户在一组图像中滑动。这个块是它的动画部分（'滑动'动画'）：

extension UIView {
func rightToLeftAnimation(_ duration: TimeInterval = 0.5, completionDelegate: AnyObject? = nil) {
    // Create a CATransition object
    let rightToLeftTransition = CATransition()

    // Set its callback delegate to the completionDelegate that was provided
    if let delegate: AnyObject = completionDelegate {
        rightToLeftTransition.delegate = delegate //ERROR MESSAGE ON THIS LINE
    }

    rightToLeftTransition.type = kCATransitionPush
    rightToLeftTransition.subtype = kCATransitionFromLeft
    rightToLeftTransition.duration = duration
    rightToLeftTransition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
    rightToLeftTransition.fillMode = kCAFillModeRemoved

    // Add the animation to the View's layer
    self.layer.add(rightToLeftTransition, forKey: "rightToLeftTransition")
}

这在 Swift 2.3 中工作得很好，但现在它不起作用了。像这样的小东西让我发疯......任何帮助将不胜感激;）

【问题讨论】：

哇，伙计们！感谢您的超快速答案，我很感激。我确信这两个答案都会奏效，但我尝试了 Rob's 并且它奏效了。非常感谢大家！

标签： swift swift3 caanimation

【解决方案1】：

现在是CAAnimationDelegate:

if let delegate = completionDelegate as? CAAnimationDelegate {
    rightToLeftTransition.delegate = delegate
}

或者只是：

func rightToLeftAnimation(_ duration: TimeInterval = 0.5, completionDelegate: CAAnimationDelegate? = nil) {
    // Create a CATransition object
    let rightToLeftTransition = CATransition()

    // Set its callback delegate to the completionDelegate that was provided
    rightToLeftTransition.delegate = completionDelegate

    rightToLeftTransition.type = kCATransitionPush
    rightToLeftTransition.subtype = kCATransitionFromLeft
    rightToLeftTransition.duration = duration
    rightToLeftTransition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
    rightToLeftTransition.fillMode = kCAFillModeRemoved

    // Add the animation to the View's layer
    layer.add(rightToLeftTransition, forKey: "rightToLeftTransition")
}

【讨论】：

【解决方案2】：

Try this , Its working in my code:

 let swipeRight:UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(ViewController.swipedRight))
        swipeRight.direction = .right
        SLIDEVIEW.addGestureRecognizer(swipeRight)


        let swipeLeft:UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(ViewController.swipedLeft))
        swipeLeft.direction = .left
        SLIDEVIEW.addGestureRecognizer(swipeLeft)

func swipedRight()
    {
        print("swiped right")
        updateFrames(towards: "right")
    }

    func swipedLeft()
    {
        print("swiped left")
        updateFrames(towards: "left")
    }

【讨论】：