编码/解码的base64德codedData =零 [英] Encoding/Decoding base64 decodedData = nil

问题描述

昨天我写了一个工作code这一点，但我将其擦除和写入一个新的东西的时候是很奇怪的：

Yesterday I wrote a working code for this, but I erased it and when writing a new one something is really weird:

我带code它的图片是这样的：

I encode it a picture this way:

let pictureData = UIImagePNGRepresentation(picture!)
let pictureToString64 = pictureData?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)

（我以前有JPEGRe presentation，但它没有工作，所以我试图用JPEG）
我去code这样通过让 PIC 64 ，我相信它有正确的值。它始于 iVBORw0KGgoAAAANSUhEUgAAAUAA （...）

(I had JPEGRepresentation before, but it wasn't working, so I tried with JPEG) and I decode this way by getting pic 64 which I believe it has the correct value. It starts with iVBORw0KGgoAAAANSUhEUgAAAUAA(...)

 let decodedData = NSData(base64EncodedString: pic64, options:NSDataBase64DecodingOptions(rawValue: 0))
 let decodedImage = UIImage(data: decodedData!)
 let pictureDataLocal = UIImageJPEGRepresentation(decodedImage!, 100)
                defaults.setObject(pictureDataLocal, forKey: "profilePicture")

的问题是，德codedData始终是零。为什么会出现这种情况？

The problem is that decodedData is always nil. Why is this happening?

推荐答案

我觉得这与做 NSDataBase64DecodingOptions 。

使用 NSDataBase64DecodingOptions.IgnoreUnknownCharacters 而不是 NSDataBase64DecodingOptions（rawValue：0），我是能够去code中的Base64编码的连接codeD字符串返回到的NSData ，并创建了一个的UIImage 从数据：

Using NSDataBase64DecodingOptions.IgnoreUnknownCharacters instead of NSDataBase64DecodingOptions(rawValue: 0), I was able to decode the Base64 encoded string back into NSData, and created a UIImage from that data:

let picture = UIImage(named: "myImage")

let pictureData = UIImagePNGRepresentation(picture!)

let pictureToString64 = pictureData?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)

let decodedData = NSData(base64EncodedString: pictureToString64!, options:NSDataBase64DecodingOptions.IgnoreUnknownCharacters)
let decodedImage = UIImage(data: decodedData!)
let pictureDataLocal = UIImageJPEGRepresentation(decodedImage!, 100)

NSDataBase64DecodingOptions 从 OptionSetType 继承这就是为什么你得到的rawValue初始化。最好是使用该组类型中的一个，而传递的值。我在 NSDataBase64DecodingOptions 是在结构中唯一的公共变种头看见了，所以我尝试了。

NSDataBase64DecodingOptions inherits from OptionSetType which is why you get the rawValue initializer. It is better to use the one of the set types, rather passing in a value. I saw in the header that NSDataBase64DecodingOptions was the only public var in the struct, so I tried it.

@available(iOS 7.0, *)
public struct NSDataBase64DecodingOptions : OptionSetType {
    public init(rawValue: UInt)

    // Use the following option to modify the decoding algorithm so that it ignores unknown non-Base64 bytes, including line ending characters.
    public static var IgnoreUnknownCharacters: NSDataBase64DecodingOptions { get }
}

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