将 base64 数据解码为图像

Question

此代码不再适用于 Swift 3。

imageData = NSData(base64EncodedString: mediaFile, options: NSDataBase64DecodingOptions.fromRaw(0)!)

这个也是。

imageData = NSData(base64EncodedString: mediaFile, options: .allZeros)

Answer 1

你可以这样写

let data = NSData(base64Encoded: mediaFile, options: NSData.Base64DecodingOptions(rawValue: 0))

希望对您有所帮助

Answer 2

不使用NSData直接使用Swift3原生Data.

if let decodedData = Data(base64Encoded: mediaFile, options: .ignoreUnknownCharacters) {
    let image = UIImage(data: decodedData)
}

Answer 3

Swift

Swift 3.0 不建议再使用 NS NSData 同样的情况

 if let decodedImageData = Data(base64Encoded: mediaFile, options: .ignoreUnknownCharacters) {
        let image = UIImage(data: decodedImageData)
    }

在Objective-C

NSURL *url = [NSURL URLWithString:base64String];    
NSData *decodedImageData = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:decodedImageData];

Answer 4

我将其实现为 UIImage 扩展

extension UIImage {

    /* 
     @brief decode image base64
     */
    static func decodeBase64(toImage strEncodeData: String!) -> UIImage {

        if let decData = Data(base64Encoded: strEncodeData, options: .ignoreUnknownCharacters), strEncodeData.characters.count > 0 {
            return UIImage(data: decData)!
        }
        return UIImage()
    }
}

Answer 5

Swift 4.1:

有时字符串有前缀data:image/png;base64会使base64Encodedreturnnil，对于这种情况：

extension String {
    func base64ToImage() -> UIImage? {
        if let url = URL(string: self),let data = try? Data(contentsOf: url),let image = UIImage(data: data) {
            return image
        }
        return nil
    }
}

演示代码：

let results = text.matches(for: "data:image\/([a-zA-Z]*);base64,([^\\"]*)")
for imageString in results {
    autoreleasepool {
        let image = imageString.base64ToImage()
    }
}

extension String {
    func matches(for regex: String) -> [String] {
        do {
            let regex = try NSRegularExpression(pattern: regex)
            let results = regex.matches(in: self, range:  NSRange(self.startIndex..., in: self))
            return results.map {
                //self.substring(with: Range([=11=].range, in: self)!)
                String(self[Range([=11=].range, in: self)!])
            }
        } catch let error {
            print("invalid regex: \(error.localizedDescription)")
            return []
        }
    }
}

PS：有关数据 uri 的更多信息：

https://en.wikipedia.org/wiki/Data_URI_scheme

https://github.com/nodes-vapor/data-uri

将 base64 数据解码为图像

Decode a base64 data to image

uiimage

base64

swift3

nsdata

xcode8