斯威夫特5

编码

func convertImageToBase64String (img: UIImage) -> String {
    return img.jpegData(compressionQuality: 1)?.base64EncodedString() ?? ""
}

解码

func convertBase64StringToImage (imageBase64String:String) -> UIImage {
    let imageData = Data(base64Encoded: imageBase64String)
    let image = UIImage(data: imageData!)
    return image!
}

注意:在xcode 10.2中测试

斯威夫特4

编码

func convertImageToBase64String (img: UIImage) -> String {
    let imageData:NSData = UIImageJPEGRepresentation(img, 0.50)! as NSData //UIImagePNGRepresentation(img)
    let imgString = imageData.base64EncodedString(options: .init(rawValue: 0))
    return imgString
}

解码

func convertBase64StringToImage (imageBase64String:String) -> UIImage {
    let imageData = Data.init(base64Encoded: imageBase64String, options: .init(rawValue: 0))
    let image = UIImage(data: imageData!)
    return image
}

注意:在xcode 9.4.1中测试

@implementation UIImage (Extended)

- (NSString *)base64String {
    NSData * data = [UIImagePNGRepresentation(self) base64EncodedDataWithOptions:NSDataBase64Encoding64CharacterLineLength];
    return [NSString stringWithUTF8String:[data bytes]];
}

@end

See my class -  AppExtension.swift


// MARK: - UIImage (Base64 Encoding)

public enum ImageFormat {
    case PNG
    case JPEG(CGFloat)
}

extension UIImage {

    public func base64(format: ImageFormat) -> String {
        var imageData: NSData
        switch format {
        case .PNG: imageData = UIImagePNGRepresentation(self)
        case .JPEG(let compression): imageData = UIImageJPEGRepresentation(self, compression)
        }
        return imageData.base64EncodedStringWithOptions(.allZeros)
    }
}

//convert Image to Base64 (Encoding)

let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)

print(strBase64)

// convert Base64 to Image (Decoding)

let dataDecoded:NSData = NSData(base64EncodedString: strBase64, options: NSDataBase64DecodingOptions(rawValue: 0))!

let decodedimage:UIImage = UIImage(data: dataDecoded)!

print(decodedimage)

yourImageView.image = decodedimage

SWIFT 3.0, XCODE 8.0

将字符串替换为URL。和testImage是ImageView的一个出口

// Put Your Image URL
let url:NSURL = NSURL(string : "http://.jpg")!
// It Will turn Into Data
let imageData : NSData = NSData.init(contentsOf: url as URL)!
// Data Will Encode into Base64
let str64 = imageData.base64EncodedData(options: .lineLength64Characters)
// Now Base64 will Decode Here
let data: NSData = NSData(base64Encoded: str64 , options: .ignoreUnknownCharacters)!
// turn  Decoded String into Data
let dataImage = UIImage(data: data as Data)
// pass the data image to image View.:)
testImage.image = dataImage

希望能有所帮助谢谢。

解码使用方便的初始化器- Swift 5

extension UIImage {
    convenience init?(base64String: String) {
        guard let data = Data(base64Encoded: base64String) else { return nil }
        self.init(data: data)
    }
}