Question

我正在尝试通过FTP在ASP.Net上传图像文件。图像文件上传到正确的位置，但是当我阅读或下载图像文件时，它已损坏。我的代码如下：

protected void FTPUpload()
{
    //FTP Server URL.
    string ftp = ConfigurationManager.AppSettings.Get("FTPServer");

    //FTP Folder name. 
    string ftpFolder = "images/logos/";

    //FTP Credentials
    string ftpUsername = ConfigurationManager.AppSettings.Get("FTPUsername");
    string ftpPassword = ConfigurationManager.AppSettings.Get("FTPPassword");

    byte[] fileBytes = null;

    //Read the FileName and convert it to Byte array.
    string fileName = Path.GetFileName(fuLogo.FileName);
    using (StreamReader fileStream = new StreamReader(fuLogo.PostedFile.InputStream))
    {
        fileBytes = Encoding.UTF8.GetBytes(fileStream.ReadToEnd());
        fileStream.Close();
    }

    try
    {
        //Create FTP Request.
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftp + ftpFolder + fileName);
        request.Method = WebRequestMethods.Ftp.UploadFile;

        //Enter FTP Server credentials.
        request.Credentials = new NetworkCredential(ftpUsername, ftpPassword);
        request.ContentLength = fileBytes.Length;
        request.UsePassive = true;
        request.UseBinary = true;
        request.ServicePoint.ConnectionLimit = fileBytes.Length;
        request.EnableSsl = false;

        using (var requestStream = request.GetRequestStream())
        {
            CopyStream(fuLogo.PostedFile.InputStream, requestStream);
        }

        FtpWebResponse response = (FtpWebResponse)request.GetResponse();

        //lblMessage.Text += fileName + " uploaded.<br />";
        response.Close();
    }
    catch (WebException ex)
    {
        throw new Exception((ex.Response as FtpWebResponse).StatusDescription);
    }
}

public static void CopyStream(Stream input, Stream output)
{
    byte[] buffer = new byte[1024000];
    int read;
    while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
    {
        output.Write(buffer, 0, read);
    }
}

我错过了什么吗？该文件已完美上传，但由于某种原因，它已损坏。

Answer 1

这部分气味：

using (StreamReader fileStream = new StreamReader(fuLogo.PostedFile.InputStream))
{
    fileBytes = Encoding.UTF8.GetBytes(fileStream.ReadToEnd());
    fileStream.Close();
}

没有理由首先将图像复制到数组（并在此期间使用默认文本编码/ UTF8解码） - 只需执行流到流的复制^{（参见How do I copy the contents of one stream to another? ）功能}：

public static void CopyStream(Stream input, Stream output)
{
    byte[] buffer = new byte[32768];
    int read;
    while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
    {
        output.Write (buffer, 0, read);
    }
}

所以ftp上传应该只是

using (var requestStream = request.GetRequestStream())
{
   CopyStream(fuLogo.PostedFile.InputStream, requestStream);
   // no need to requestStream.Close(); - using does that for you
}

ASP.Net FTP上传不起作用

1 个答案: