图片 base64转byte[]

		/// <summary>
        /// 保存base64图片,返回阿里云地址
        /// </summary>
        /// <param name="imgCode"></param>
        /// <returns></returns>
        private string SaveBase64Image(string imgCode)
        {
            string imgUrl = string.Empty;
            if (!string.IsNullOrEmpty(imgCode))
            {
                Regex reg = new Regex(@"data:(image.+);base64,(.+)");
                if (reg.IsMatch(imgCode))
                {
                    var matchs = reg.Match(imgCode);
                    string contentType = matchs.Groups[1].Value;
                    string base64Code = matchs.Groups[2].Value;
                    string extendType = contentType.Replace("image/", "");
                    byte[] arr = Convert.FromBase64String(base64Code);//base64转byte[]
                    //var picture = _pictureService.InsertPicture(arr, extendType);
                }
            }
            return imgUrl;
        }

Stream转byte[]

 		/// <summary>
        /// StreamToBytes
        /// </summary>
        /// <param name="stream"></param>
        /// <returns></returns>
        public static byte[] StreamToBytes(Stream stream)
        {
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            // 设置当前流的位置为流的开始
            stream.Seek(0, SeekOrigin.Begin);
            return bytes;
        }

byte[]转base64

var base64Url = Convert.ToBase64String(avatarData);//avatarData为byte[]

base64转byte[]

byte[] data = Convert.FromBase64String(signedString);

file转base64

			var requestFiles = Request.Files;
            if (requestFiles.Count > 0)
            {
                var avatarData = CommonHelper.StreamToBytes(requestFiles[0].InputStream);//Stream转byte[]
                var base64Url = Convert.ToBase64String(avatarData);//byte[]转base64
            }