void Base64StringToImage(string imgCode)

        {

            try

            {

                String inputStr = imgCode;

                byte[] arr = Convert.FromBase64String(inputStr);

                MemoryStream ms = new MemoryStream(arr);

                Bitmap bmp = new Bitmap(ms);

                //bmp.Save(txtFileName + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);

                //bmp.Save(txtFileName + ".bmp", ImageFormat.Bmp);

                //bmp.Save(txtFileName + ".gif", ImageFormat.Gif);

                //bmp.Save(txtFileName + ".png", ImageFormat.Png);

                ms.Close();

                this.pictureBox1.Image = bmp;

                //MessageBox.Show("转换成功！");

            }

            catch (Exception ex)

            {

                MessageBox.Show("Base64StringToImage 转换失败\nException：" + ex.Message);

            }

        }