苦苦挣扎将Objective C选择器和目标签名转换为Swift [英] Struggling to convert Objective C selector and target signature to Swift

问题描述

美好的一天，

我正在尝试将Objective C片段转换为Swift。我理解选择器可以通过将它放在一个字符串中直接翻译，但我无法理解Objective C签名。：

I am trying to convert an Objective C snippet to Swift. I understand the selector can be translated directly by placing it in a string, but I cannot understand the Objective C signature.:

Objectice C选择器（第二个参数）：

The Objectice C selector (2nd parameter):

UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

目标：

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{

我的问题是：
1.我只需将选择器传递给：

My Questions are: 1.Can I simply pass the selector as :

UIImageWriteToSavedPhotosAlbum(image, self, "image:didFinishSavingWithError:contextInfo:", nil);

2.请帮我解决目标函数的问题。我很难过！

2.Please help me with the singnature of the target function. I am stumped!

推荐答案

要从Objective-C方法名称转换为Swift，Objective C方法中的第一个参数名称变为函数名称，然后其余参数成为函数的参数。

To convert from an Objective-C method name to Swift the first parameter name in the Objective C method becomes the function name and then the remaining parameters become the parameters of the function.

在您的情况下，第一个参数名称是 image ，因此Swift中的函数名称将是 image 。

In your case, the first parameter name is image, so the function name in Swift will be image.

所以，

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo

变得有些奇怪 -

func image(image: UIImage, didFinishSavingWithError: NSError, contextInfo:UnsafePointer<Void>)       {

}

为了使事情变得简单，你可以使用不同的内部参数名称来表示错误 -

To make things a bit simpler, you an use a different internal parameter name for the error -

func image(image: UIImage, didFinishSavingWithError error: NSError, contextInfo:UnsafePointer<Void>)       {

}

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