Question

在这里遇到问题，再一次认为我接近解决方案，但是它让我不知所措。

我正在尝试从WCF服务获取文件流后从我们的ASP.NET网站下载Excel文件。这似乎工作正常，但我可能会采取完全错误的方式。

在代码中使用断点我能够看到文件到达方法并被“流式”传输到浏览器，但是它无法下载（当角落里出现小图标时，或者出现提示，具体取决于浏览器。）

我尝试调整此代码http://www.codeproject.com/Articles/166763/WCF-Streaming-Upload-Download-Files-Over-HTTP以接受.xls文件。

这是我的FileTransfer.cs和IFileTransfer.cs WCF类。 FileTransfer.cs

public RemoteFileData DownloadFile(DownloadRequest request)
            {
                RemoteFileData result = new RemoteFileData();
                try
                {
                    string filePath = System.IO.Path.Combine(@"C:\Files", request.FileName);
                    System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

                    // does file exist?
                    if (!fileInfo.Exists)
                        throw new System.IO.FileNotFoundException("File not found", request.FileName);

                    // open the stream
                    System.IO.FileStream stream = new System.IO.FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read);

                    // return result over the stream
                    result.FileName = request.FileName;
                    result.Length = fileInfo.Length;
                    result.FileByteStream = stream;
                }
                catch (Exception ex)
                {
                }
                return result;
            }

IFileTransfer.cs

[ServiceContract]

public interface IFileTransfer
{
    [OperationContract]
    RemoteFileData DownloadFile(DownloadRequest request);
}

[MessageContract]
public class DownloadRequest
{
    [MessageBodyMember]
    public string FileName;
}

[MessageContract]
public class RemoteFileData : IDisposable
{
    [MessageHeader(MustUnderstand = true)]
    public string FileName;

    [MessageHeader(MustUnderstand = true)]
    public long Length;

    [MessageBodyMember(Order = 1)]
    public System.IO.Stream FileByteStream;

    public void Dispose()
    {
        if (FileByteStream != null)
        {
            FileByteStream.Close();
            FileByteStream = null;
        }
    }
}

这是Linkbutton方法/事件。

protected void LnkBtn_genPAFFile_Click(object sender, EventArgs e)
{
    try
    {
        GSIISFileTransferService.IFileTransfer tClient = new GSIISFileTransferService.FileTransferClient();
        GSIISFileTransferService.DownloadRequest requestData = new GSIISFileTransferService.DownloadRequest();
        GSIISFileTransferService.RemoteFileData fileInfo = new GSIISFileTransferService.RemoteFileData();

        requestData.FileName = "form.xls";
        fileInfo = tClient.DownloadFile(requestData);

        Response.BufferOutput = false;
        byte[] buffer = new byte[6500];
        int bytesRead = 0;

        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.ClearHeaders();
        HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
        HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + requestData.FileName);

        bytesRead = fileInfo.FileByteStream.Read(buffer, 0, buffer.Length);

        while (bytesRead > 0)
        {
            if (Response.IsClientConnected)
            {
                Response.OutputStream.Write(buffer, 0, bytesRead);
                // flush data to HTML
                Response.Flush();

                buffer = new byte[6500];
                bytesRead = fileInfo.FileByteStream.Read(buffer, 0, buffer.Length);
            }
            else
            {
                bytesRead = -1;
            }
        }
    }
    catch (Exception ex)
    {
        System.Web.HttpContext.Current.Response.Write("Error : " + ex.Message);
    }
    finally
    {
        Response.Flush();
        Response.Close();
        Response.End();
        System.Web.HttpContext.Current.Response.Close();
    }
}

Answer 1

我假设您已为excel文件配置了MIME类型。您可以从此处查看如何创建MIME类型：

http://technet.microsoft.com/en-us/library/cc725608(WS.10).aspx

此外，在您的IIS中，如果您使用的是SSL，则在“HTTP标头”选项卡上的“自定义HTTP标头”下，您应该看到＆＃34; Cache-Control no-cache＆＃34;指定。你应该删除该选项。

你也可以试试这个：

HttpContext.Current.Response.AddHeader("Content-Type: application/octet-stream");

此八位字节流内容类型强制IE下载文件。

从WCF服务获取Excel后，流式Excel文件以供下载

1 个答案: