C# 图片与Base64的相互转化

public ActionResult UploadSignature2(string src_data)        {            Class1.Base64StrToImage(src_data, "C:\\Users\\45448\\Desktop\\1\\"+ DateTime.Now.ToString("yyyyMMddHHss") + ".png");            return Json(1, JsonRequestBehavior.AllowGet);        }        /// <summary>        /// 将Base64字符串转换为图片并保存到本地        /// </summary>        /// <param name="base64Str">base64字符串</param>        /// <param name="savePath">图片保存地址，如：/Content/Images/10000.png</param>        /// <returns></returns>        public static bool Base64StrToImage(string base64Str, string savePath)        {            var ret = true;            try            {                base64Str = base64Str.Replace("data:image/png;base64,", "").Replace("data:image/jgp;base64,", "")                    .Replace("data:image/jpg;base64,", "").Replace("data:image/jpeg;base64,", ""); //将base64头部信息替换                var bitmap = Base64StrToImage(base64Str);                if (bitmap != null)                {                    //创建文件夹                    var folderPath = savePath.Substring(0, savePath.LastIndexOf('\\'));                    ////FileHelper.CreateDir(folderPath);                    if (!Directory.Exists(folderPath))                    {                        Directory.CreateDirectory(folderPath);                    }                    //图片后缀格式                    var suffix = savePath.Substring(savePath.LastIndexOf('.') + 1,                        savePath.Length - savePath.LastIndexOf('.') - 1).ToLower();                    var suffixName = suffix == "png"                        ? ImageFormat.Png                        : suffix == "jpg" || suffix == "jpeg"                            ? ImageFormat.Jpeg                            : suffix == "bmp"                                ? ImageFormat.Bmp                                : suffix == "gif"                                    ? ImageFormat.Gif                                    : ImageFormat.Jpeg;                    //这里复制一份对图像进行保存，否则会出现“GDI+ 中发生一般性错误”的错误提示                    var bmpNew = new Bitmap(bitmap);                    bmpNew.Save(savePath, suffixName);                    bmpNew.Dispose();                    bitmap.Dispose();                }                else                {                    ret = false;                }            }            catch (Exception ex)            {                ret = false;            }            return ret;           }复制代码复制代码 /// <summary>        /// Image 转成 base64        /// </summary>        /// <param name="fileFullName"></param>        public static string ImageToBase64(string fileFullName)        {            try            {                Bitmap bmp = new Bitmap(fileFullName);                MemoryStream ms = new MemoryStream();                var suffix = fileFullName.Substring(fileFullName.LastIndexOf('.') + 1,                    fileFullName.Length - fileFullName.LastIndexOf('.') - 1).ToLower();                var suffixName = suffix == "png"                    ? ImageFormat.Png                    : suffix == "jpg" || suffix == "jpeg"                        ? ImageFormat.Jpeg                        : suffix == "bmp"                            ? ImageFormat.Bmp                            : suffix == "gif"                                ? ImageFormat.Gif                                : ImageFormat.Jpeg;                bmp.Save(ms, suffixName);                byte[] arr = new byte[ms.Length]; ms.Position = 0;                ms.Read(arr, 0, (int)ms.Length); ms.Close();                return Convert.ToBase64String(arr);            }            catch (Exception ex)            {                return null;            }        }