从网址下载.xls文件

Question

我正在尝试从网址下载xls文件：http://www.site.com/ff/excel/file.aspx?deven=0

我正在使用此代码，但是下载完成后，文件未正确下载。如何正确下载此文件？

string remoteFilename="http://www.site.com/ff/excel/file.aspx?deven=0";
string localFilename = "D:\1\1.xls";
Stream remoteStream = null;
Stream localStream = null;
WebResponse response = null;
try
{
    // Create a request for the specified remote file name
    WebRequest request = WebRequest.Create(remoteFilename);
    if (request != null)
    {
        // Send the request to the server and retrieve the
        // WebResponse object 
        response = request.GetResponse();
        response.ContentType = "application/vnd.ms-excel";
        if (response != null)
        {
            // Once the WebResponse object has been retrieved,
            // get the stream object associated with the response's data
            remoteStream = response.GetResponseStream();
            // Create the local file
            localStream = File.Create(localFilename);
            // Allocate a 1k buffer
            byte[] buffer = new byte[1024];
            int bytesRead;
            // Simple do/while loop to read from stream until
            // no bytes are returned
            do
            {
                // Read data (up to 1k) from the stream
                bytesRead = remoteStream.Read(buffer, 0, buffer.Length);
                // Write the data to the local file
                localStream.Write(buffer, 0, bytesRead);
                // Increment total bytes processed
            } while (bytesRead > 0);
        }
    }
}
catch (Exception e)
{
    MessageBox.Show(e.Message);
}
finally
{
    // Close the response and streams objects here 
    // to make sure they're closed even if an exception
    // is thrown at some point
    if (response != null) response.Close();
    if (remoteStream != null) remoteStream.Close();
    if (localStream != null) localStream.Close();
}
MessageBox.Show("file downl");

Answer 1

使用 WebClient，它要简单得多：

using (WebClient webClient = new WebClient())
{
    webClient.DownloadFile(remoteFileName, localFilename);
}
if(File.Exists(localFilename))
    MessageBox.Show("File Downloaded");

Answer 2

尝试在

do {} while()后用localStream.Flush()刷新，您可能还想用 using 语句括起来。

例如：

// Create the local file
using (localStream = File.Create(localFilename)) {
    // Allocate a 1k buffer
   byte[] buffer = new byte[1024];
   int bytesRead;
   // Simple do/while loop to read from stream until
   // no bytes are returned
   do {
       // Read data (up to 1k) from the stream
       bytesRead = remoteStream.Read(buffer, 0, buffer.Length);
        // Write the data to the local file
        localStream.Write(buffer, 0, bytesRead);
        // Increment total bytes processed
    } while (bytesRead > 0);
    localStream.Flush();
}

Answer 3

这就是我使用 FilePathResult 下载 Excel 文件的方式。

public FilePathResult DownloadFile(int ID)
{
    var log = _db.Logs.FirstOrDefault(x => x.LogID == ID);
    //Download the spreadsheet
    string fileName = string.Format("{0}.xlsx", ID);
    string path = _directory + "\" + fileName;
    return File(path, "application/vnd.ms-excel", string.Format("{0}.xlsx", log.ReportTitle));
}