Safari 不能播放Video ,Chrome等能夠 問題解決。

1  緣由分析

      https://www.zhihu.com/question/41818719

2 代碼實現

   1 注意點： 請求時 ： header中 range 請求多少長度 代碼要返回相應的長度  好比Byte 0-1

  /// <summary>
        /// 返回mp4 兼容蘋果 
        /// </summary>
        /// <param name="context"></param>
        /// <param name="filePath"></param>
        private void CreateVideoResponse(HttpContext context, string filePath)
        {
            var reqRange = context.Request.Headers["Range"];
            string[] reqBlockRange = null;
            if (!string.IsNullOrEmpty(reqRange))
            {
                reqBlockRange = reqRange.Replace("bytes=", "").Split(new[] { "-"},StringSplitOptions.RemoveEmptyEntries);
                context.Response.StatusCode = 206;
                context.Response.AddHeader("status", "206");
            }
            using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            using (var reader = new BinaryReader(stream))
            {
                long fileSize = stream.Length;

                long startPosition = 0;
                long partialSize = fileSize;
                if (reqBlockRange != null)
                {
　　　　　　　　　　　　//safari 
                    startPosition = Convert.ToInt64(reqBlockRange[0]);
                    if(reqBlockRange.Length > 1)
                    {
                        long endPosition = fileSize;
                        if (long.TryParse(reqBlockRange[1], out endPosition))
                        {
                            partialSize = endPosition - startPosition + 1;
                        }
                    }else
                    {
　　　　　　　　　　　　　　// chrome 等
                        partialSize = fileSize - startPosition;
                    }
                }

                byte[] buffer = new byte[(int)partialSize];
                reader.BaseStream.Seek(startPosition, SeekOrigin.Begin);
                reader.Read(buffer, 0, (int)partialSize);

                context.Response.AddHeader("accept-ranges", "bytes");
                context.Response.AddHeader("access-control-allow-methods", "HEAD, GET, OPTIONS");
                context.Response.AddHeader("cache-control", "public, max-age=30726563");
                context.Response.ContentType = "video/mp4";
                context.Response.Cache.SetLastModified(DateTime.Now);
                context.Response.AddHeader("Connection", "keep-alive");
                context.Response.AddHeader("content-range", $"bytes {startPosition}-{startPosition + partialSize-1 }/{fileSize}");
                context.Response.AddHeader("Content-Length", $"{partialSize}");
                context.Response.BinaryWrite(buffer);
            }
          
        }