将功能传递到完成处理程序

Question

我具有在视图上执行动画的函数。我想实现此功能的完成处理程序，该功能在动画完成后将被调用。

在ViewController中...

hudView.hide(animated: true, myCompletionHandler: {
    // Animation is complete
})

在Hudview类中...

func hide(animated: Bool, myCompletionHandler: () -> Void) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)
        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: nil) // I want to run 'myCompletionHandler' in this completion handler
    }
}

我已经尝试了许多事情，但找不到正确的语法：

}, completion: myCompletionHandler)

传递非排行参数" mycompletionhandler"以期望 @escaping闭合

}, completion: myCompletionHandler())

无法将'void'类型的值转换为预期参数类型'（（bool） -> void）？'

}, completion: { myCompletionHandler() })

关闭非排放参数" mycompletionhandler"可能允许它 逃脱

作为迅速的新手，这些错误消息对我来说意义不大，我似乎找不到任何正确方法的示例。

将myCompletionHandler传递给.animate完成处理程序的正确方法是什么？

Answer 1

如果要将自己的封闭方式作为输入参数传递给UIView.animate，则需要匹配封闭类型，因此myCompletionHandler必须具有((Bool) -> ())?的类型，就像completion一样。

func hide(animated: Bool, myCompletionHandler: ((Bool) -> ())?) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)
        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: myCompletionHandler) // I want to run 'myCompletionHandler' in this completion handler
    }
}

这就是您可以调用它的方式：

hudView.hide(animated: true, myCompletionHandler: { success in
    //animation is complete
})

Answer 2

这是在uiview.animate中使用完成的方法：

func hide(animated: Bool, myCompletionHandler: () -> Void) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)
        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: { (success) in
            myCompletionHandler()
        })
    }
}

Answer 3

You can create your function as,
func hide(_ animated:Bool, completionBlock:((Bool) -> Void)?){
}
And you can call it as,
self.hide(true) { (success) in
   // callback here     
}