WCF下載文件被客戶端中止

Question

我有以下用於下載大文件的代碼。 它從文件流讀取並寫入Response.Outputstream。

它似乎正在運行，即文件似乎下載了（實際上，似乎很奇怪地下載了更多文件），但最終失敗了。 Chrome給出“網絡錯誤”，而IE顯示“（已中止）”

    [OperationContract]
    [WebInvoke(UriTemplate = "/f/{key}", Method = "GET")]
    public void LargeFileDownload(string key)
    {
        var identifier = PublicIdentifier.FromString(key, true);
        if (identifier.Type == PublicIdentifier.IdentifierType.DocumentDownload)
        {
            Document doc = Business.Documents.GetById(Application.SystemUser, identifier.Id);

            string tempName = Path.GetTempPath() + doc.OriginalFileName;

            int bufferSize = 8192;
            FileStream fstream = new FileStream(tempName, FileMode.Open, FileAccess.Read);
            long fileSize = fstream.Length;

            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.ClearContent();
            HttpContext.Current.Response.ContentType = doc.ContentType;

            string contentDisposition = string.Format("{0};filename={1}{2}", "attachment", doc.Name.Replace(" ", "_"), Path.GetExtension(doc.OriginalFileName));
            HttpContext.Current.Response.AddHeader("Content-Disposition", contentDisposition);
            HttpContext.Current.Response.AddHeader("Content-Length", fileSize.ToString());

            WebOperationContext.Current.OutgoingResponse.ContentType = doc.ContentType;
            try
            {
                byte[] buffer = new byte[bufferSize];

                int bytesRead = 0;
                while ((bytesRead = fstream.Read(buffer, 0, bufferSize)) > 0)
                {
                    HttpContext.Current.Response.OutputStream.Write(buffer, 0, bufferSize);
                    HttpContext.Current.Response.Flush();
                }
            }
            finally
            {
                if (fstream != null)
                    fstream.Close();

                //File.Delete(tempName);
            }
        }
    }

更新的代碼：-

    [OperationContract]
    [WebInvoke(UriTemplate = "/f/{key}", Method = "GET")]
    public void LargeFileDownload(string key)
    {
        var identifier = PublicIdentifier.FromString(key, true);
        if (identifier.Type == PublicIdentifier.IdentifierType.DocumentDownload)
        {
            Document doc = Business.Documents.GetById(Application.SystemUser, identifier.Id);

            string tempName = Path.GetTempPath() + doc.OriginalFileName;

            int bufferSize = 8192;
            FileStream fstream = new FileStream(tempName, FileMode.Open, FileAccess.Read);
            long fileSize = fstream.Length;

            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.ClearContent();
            HttpContext.Current.Response.ContentType = "application/octet-stream";

            string contentDisposition = string.Format("{0};filename={1}{2}", "attachment", doc.Name.Replace(" ", "_"), Path.GetExtension(doc.OriginalFileName));
            HttpContext.Current.Response.AddHeader("Content-Disposition", contentDisposition);
            HttpContext.Current.Response.AddHeader("Content-Length", fileSize.ToString());

            HttpContext.Current.Response.ContentType = "application/octet-stream";
            try
            {
                byte[] buffer = new byte[bufferSize];

                int bytesRead = 0;
                while ((bytesRead = fstream.Read(buffer, 0, bufferSize)) > 0)
                {
                    HttpContext.Current.Response.OutputStream.Write(buffer, 0, bytesRead);
                    HttpContext.Current.Response.Flush();
                }
            }
            finally
            {
                if (fstream != null)
                    fstream.Close();

                //File.Delete(tempName);
            }
        }
    }

提琴手原始：-

HTTP/1.1 504 Fiddler - Receive Failure
Date: Wed, 17 Oct 2018 11:53:09 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Cache-Control: no-cache, must-revalidate
Timestamp: 12:53:09.099

[Fiddler] ReadResponse() failed: The server did not return a complete response for this request. Server returned 13,912,938 bytes.

Answer 1

您正確設置了Content-Length ，瀏覽器假定該值為true。 但是由於這個錯誤，您正在發送更多數據（這是垃圾）：

HttpContext.Current.Response.OutputStream.Write(buffer, 0, bufferSize);

這不應該是bufferSize而應該是bytesRead 。 這導致協議錯誤，導致瀏覽器中止其處理。

復制循環可能應該由對TransmitFile的調用或至少由Stream.Copy 。