如何使用靜態函數與完成處理程序調用UIImageWriteToSavedPhotosAlbum（）？

Question

我能夠調用UIImageWriteToSavedPhotosAlbum和處理完成沒有問題：

class A { 
    func saveNow() { 
     UIImageWriteToSavedPhotosAlbum(someImage, self, "saveImage:didFinishSavingWithError:contextInfo:", nil) 
    } 

    func saveImage(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo:UnsafePointer<Void>) { 
     // handle completion 
    } 
} 

不過，如果我想使saveNow()靜態函數，我不能夠正確地設定completionTarget & completionSelector，這樣我可以處理完成：

class B { 
    static func saveNow() { 
     UIImageWriteToSavedPhotosAlbum(someImage, /* how to set here */) 
    } 

    static func saveImage completionSelector(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo:UnsafePointer<Void>) { 
    } 
} 

如何修改B類如果我想使用靜態函數？

Answer 1

您需要做的是將目標設置爲YourClassName.self。

也就是說，

UIImageWriteToSavedPhotosAlbum(someImage, YourClassName.self, "saveImage:didFinishSavingWithError:contextInfo:", nil) 

順便說一句，你的函數名是不正確的：

//Note the space between saveImage and completionSelector 
static func saveImage completionSelector(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo:UnsafePointer<Void>) 

我覺得應該是：

static func saveImageWithCompletionSelector(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo:UnsafePointer<Void>) 

因此，我們可能需要做出相應更改：

UIImageWriteToSavedPhotosAlbum(someImage, YourClassName.self, "saveImageWithCompletionSelector:didFinishSavingWithError:contextInfo:", nil) 

我剛剛進行了上述更改和建議的快速測試;應該彈出一個請求訪問相冊的授權。