Swift UIImage和Base64字符串互转

 //Base64转UIImage
   class func convertStrToImage(_ imageStr:String) ->UIImage?{
        if let data: NSData = NSData(base64Encoded: imageStr, options:NSData.Base64DecodingOptions.ignoreUnknownCharacters)
        {
            if let image: UIImage = UIImage(data: data as Data)
            {
                return image
            }
        }
        return nil
    }

    
    //UIImage转Base64
    class func getStrFromImage(_ imageStr:String) -> String{
        let imageOrigin = UIImage.init(named: imageStr)
        if let image = imageOrigin {
            let dataTmp = image.pngData()
            if let data = dataTmp {
                let imageStrTT = data.base64EncodedString()
                return imageStrTT
            }
        }
        return ""
    }