用于base64转换的Swift UIImage扩展

public enum ImageFormat {
    case png
    case jpeg(CGFloat)
}

extension UIImage {
    
    public func base64(format: ImageFormat) -> String? {
        var imageData: Data?
        switch format {
        case .png: imageData = UIImagePNGRepresentation(self)
        case .jpeg(let compression): imageData = UIImageJPEGRepresentation(self, compression)
        }
        return imageData?.base64EncodedString()
    }
}