如何将原始值7强制为UIViewAnimationCurve枚举？ [英] How to force a raw value of 7 into a UIViewAnimationCurve enum?

问题描述

UIKeyboardWillShowNotification 的用户信息字典中的键$ UIKeyboardAnimationCurveUserInfoKey 包含一个 Int $ 7 。

The key UIKeyboardAnimationCurveUserInfoKey in the userInfo dictionary of a UIKeyboardWillShowNotification contains an Int with the value 7.

现在我需要传递这个 Int into UIView.setAnimationCurve（< here>）。我试图用这个 UIViewAnimationCurve（rawValue：7）创建所需的UIViewAnimationCurve枚举。因为原始值 7 没有记录，所以结果总是 nil 。

Now I need to pass this Int into UIView.setAnimationCurve(<here>). I tried to create the required UIViewAnimationCurve enum like this UIViewAnimationCurve(rawValue: 7). Because the raw value 7 is undocumented, the result is always nil.

在Objective-C中，这样工作正常。任何想法如何将该动画曲线从通知转换成使用Swift的UIView动画？

It works fine this way in Objective-C. Any idea how to get this animation curve from the notification into a UIView animation using Swift?

更新： As Martin指出，自从Xcode 6.3开始，这不再是一个问题。

Update: As pointed out by Martin, this is no longer a problem since Xcode 6.3.

从 Xcode 6.3发行说明：

现在可以使用init（rawValue :)初始化程序从原始整数值转换带有未记录值的导入的NS_ENUM类型，例如UIViewAnimationCurve，而不会重置为nil。使用unsafeBitCast作为此问题的解决方法的代码可以写入使用原始值初始化器。

Imported NS_ENUM types with undocumented values, such as UIViewAnimationCurve, can now be converted from their raw integer values using the init(rawValue:) initializer without being reset to nil. Code that used unsafeBitCast as a workaround for this issue can be written to use the raw value initializer.

推荐答案

我想我想出来了，但我不知道这是否应该是这样做的。

I think I figured it out, but I'm not sure if this is the way it's supposed to be done.

let animationCurve = unsafeBitCast(7, UIViewAnimationCurve.self)
UIView.setAnimationCurve(animationCurve)

更新：此质询也是如此。

var animationCurve = UIViewAnimationCurve.EaseInOut
NSNumber(integer: 7).getValue(&animationCurve)

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