從網址下載.xls文件

Question

我正在嘗試從網址下載xls文件： http : //www.site.com/ff/excel/file.aspx? deven =0

我正在使用此代碼，但是下載完成后，文件沒有正確下載。 如何正確下載此文件？

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 ，它要簡單得多：

using (WebClient webClient = new WebClient())
{
    webClient.DownloadFile(remoteFileName, localFilename);
}

if(File.Exists(localFilename))
    MessageBox.Show("File Downloaded");

Answer 2

嘗試在do {} while() localStream.Flush()之后使用localStream.Flush()刷新，您可能還希望using語句進行包裝。

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

這就是我使用FilePathResult下載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));
}