/// <summary>
        /// 图片转base 64
        /// </summary>
        /// <param name="fileFullName"></param>
        /// <returns></returns>
        public string ImageToBase64(string fileFullName)
        {
            FileInfo file = new FileInfo(@"F:\www.jxszl.com.jpg");
            var stream = file.OpenRead();
            byte[] buffer = new byte[file.Length];
            //读取图片字节流
            stream.Read(buffer, 0, Convert.ToInt32(file.Length));
            //将base64字符串保存到base64.txt文件中
            StreamWriter sw = new StreamWriter("base64.txt", false, Encoding.UTF8);
            //将字节流转化成base64字符串
            //sw.Write(Convert.ToBase64String(buffer));
            sw.Close();
            return "data:image/jpeg;base64," + Convert.ToBase64String(buffer);
        }
原文链接：http://www.jxszl.com/biancheng/C/165377.html