/// <summary>        /// 根据base64字符串返回一个封装好的GDI+位图。        /// </summary>        /// <param name="base64string">可转换成位图的base64字符串。</param>        /// <returns>Bitmap对象。</returns>        public Bitmap GetImageFromBase64(string base64string)        {            byte[] b = Convert.FromBase64String(base64string);            MemoryStream ms = new MemoryStream(b);            Bitmap bitmap = new Bitmap(ms);            return bitmap;        }        /// <summary>        /// 将图片转换成base64字符串。        /// </summary>        /// <param name="imagefile">需要转换的图片文件。</param>        /// <returns>base64字符串。</returns>        public string GetBase64FromImage(string imagefile)        {            string strbaser64 = "";            try            {                Bitmap bmp = new Bitmap(imagefile);                using (MemoryStream ms = new MemoryStream())                {                    bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);                    byte[] arr = new byte[ms.Length];                    ms.Position = 0;                    ms.Read(arr, 0, (int)ms.Length);                    ms.Close();                    strbaser64 = Convert.ToBase64String(arr);                }            }            catch (Exception)            {                throw new Exception("Something wrong during convert!");            }            return strbaser64;        }