使用WCF服务将大文件传输到Sharepoint WebPart

Question

Scenario: The client (SharePoint Webpart) should provide a download to the user. Because of security reasons I can't access the file directly from the SharePoint Webpart. So I created an wcf webservice which sends the file as stream. But this dosen't work with bigger files.

WCF Webservice send Methode:

public Stream GetFileStream(string filePath)
{
        WebClient client = new WebClient();
        return client.OpenRead(filePath);
}

The client (SharePoint Webpart) get the stream and convert it in byte[] so I can create a download in the browser.

private void SendFileToBrowser(string filePath)
    {
        Page.Response.Clear();
        Page.Response.ClearContent();
        Page.Response.ClearHeaders();
        Page.Response.ContentType = "application/pdf";
        Page.Response.AddHeader("Content-Disposition", string.Format("attachment; fileName=\"{0}\"", Path.GetFileName(filePath)));
        Page.Response.AddHeader("Accept-Ranges", "bytes");

        byte[] buffer;

        CustomBinding binding = new CustomBinding();
        BinaryMessageEncodingBindingElement binaryMsg = new BinaryMessageEncodingBindingElement();
        binaryMsg.ReaderQuotas.MaxDepth = 2147483647;
        binaryMsg.ReaderQuotas.MaxStringContentLength = 2147483647;
        binaryMsg.ReaderQuotas.MaxArrayLength = 2147483647;
        binaryMsg.ReaderQuotas.MaxBytesPerRead = 2147483647;
        binaryMsg.ReaderQuotas.MaxNameTableCharCount = 2147483647;
        binding.Elements.Add(binaryMsg);

        HttpTransportBindingElement transportBinding = new HttpTransportBindingElement();
        transportBinding.TransferMode = TransferMode.Streamed;
        transportBinding.MaxReceivedMessageSize = 2147483647;
        binding.Elements.Add(transportBinding);

        EndpointAddress endPoint = new EndpointAddress ("http://xxx/fileservice.svc");
        FileServiceClient fileServiceProxy = new FileServiceClient(binding, endPoint);

        // Stream
        Stream stream = fileServiceProxy.GetFileStream(filePath);

        fileServiceProxy.Close();

        // convert stream to byte[]
        using (var memoryStream = new MemoryStream())
        {
            stream.CopyTo(memoryStream);
            buffer = memoryStream.ToArray();
        }

        if (buffer != null)
        {
            Page.Response.BinaryWrite(buffer);
        }

        Page.Response.Flush();
        Page.Response.Close();
        Page.Response.End();
    }

The code works if the files are smaller > 300kb. But if the files are bigger (eg 50mb) it dosen't work always. But it works sometimes!??? I don't not what's wrong?

Answer 1

After some testing I uncommented the following 2 lines at the end. Now it is working.

    Page.Response.Flush();
    //Page.Response.Close();
    //Page.Response.End();