从 FTP 上传文件和下载文件

Question

我正在尝试制作一个将.exe 文件上传/下载到FTP 的程序

我尝试使用FtpWebRequest，但我只能成功上传和下载.txt文件。

然后我在这里找到了使用WebClient进行下载的解决方案：

WebClient request = new WebClient();
request.Credentials = new NetworkCredential("username", "password");
byte[] fileData =  request.DownloadData("ftp://myFTP.net/");

FileStream file = File.Create(destinatie);
file.Write(fileData, 0, fileData.Length);

file.Close();

此解决方案有效。但我看到WebClient 有一个方法DownloadFile 没有用。我认为因为它仅在HTTP 上不适用于FTP。我的假设是真的吗？如果不是，我怎样才能让它工作？

还有其他解决方案可以使用FtpWebRequest 将.exe 文件上传/下载到ftp 吗？

Answer 1

您需要说明您上传的是文本文件还是二进制文件。 在声明和初始化请求后添加以下行：

request.UseBinary = true;

http://msdn.microsoft.com/en-us/library/system.net.ftpwebrequest.usebinary.aspx

Answer 2

上传很容易...

void Upload(){
    Web client = new WebClient();
    client.Credentials = new NetworkCredential(username, password);
    client.BaseAddress = "ftp://ftpsample.net/";

    client.UploadFile("sample.txt", "sample.txt"); //since the baseaddress
}

---

下载也很简单... 我在下面制作的代码使用BackgroundWorker（因此下载开始时它不会冻结界面/应用程序）。另外，我使用lambda(=>) 缩短了代码。

void Download(){
    Web client = new WebClient();
    client.Credentials = new NetworkCredential(username, password);

    BackgroundWorker bg = new BackgroundWorker();
    bg.DoWork += (s, e) => { 
        client.DownloadFile("ftp://ftpsample.net/sample.zip", "sample.zip"); 
    };
    bg.RunWorkerCompleted += (s, e) => { //when download is completed
        MessageBox.Show("done downloading");
        download1.Enabled = true; //enable download button
        progressBar.Value = 0; // reset progressBar
    };
    bg.RunWorkerAsync();
    download1.Enabled = false; //disable download button 
    while (bg.IsBusy)
    {
        progressBar.Increment(1); //well just for extra/loading
        Application.DoEvents(); //processes all windows messages currently in the message queue
    }
}

您也可以使用DownloadFileAsync方法来显示真实的文件下载进度：

client.DownloadFileAsync(new Uri("ftp://ftpsample.net/sample.zip"), "sample.zip");
client.DownloadProgressChanged += (s, e) =>
{
    progressBar.Value = e.ProgressPercentage; //show real download progress
};
client.DownloadFileCompleted += (s, e) =>
{
    progressBar.Visible = false;
    // other codes after the download
};
//You can remove the 'while' statement and use this ^

Answer 3

WebClient.UploadFile 和 WebClient.DownloadFile 都可以正确处理 FTP 和二进制文件。

---

上传

WebClient client = new WebClient();
client.Credentials = new NetworkCredential("username", "password");
client.UploadFile(
    "ftp://ftp.example.com/remote/path/file.zip", @"C:\local\path\file.zip");

如果您需要WebClient 不提供的更大控制（如TLS/SSL encryption、ascii/文本传输模式、传输恢复等），请使用FtpWebRequest。简单的方法是使用Stream.CopyTo 将FileStream 复制到FTP 流：

FtpWebRequest request =
    (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.UploadFile;  

using (Stream fileStream = File.OpenRead(@"C:\local\path\file.zip"))
using (Stream ftpStream = request.GetRequestStream())
{
    fileStream.CopyTo(ftpStream);
}

如果你需要监控一个上传进度，你必须自己分块复制内容：

FtpWebRequest request =
    (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.UploadFile;  

using (Stream fileStream = File.OpenRead(@"C:\local\path\file.zip"))
using (Stream ftpStream = request.GetRequestStream())
{
    byte[] buffer = new byte[10240];
    int read;
    while ((read = fileStream.Read(buffer, 0, buffer.Length)) > 0)
    {
        ftpStream.Write(buffer, 0, read);
        Console.WriteLine("Uploaded {0} bytes", fileStream.Position);
    } 
}

有关 GUI 进度 (WinForms ProgressBar)，请参阅：
How can we show progress bar for upload with FtpWebRequest

如果您想上传文件夹中的所有文件，请参阅
Recursive upload to FTP server in C#。

---

下载

WebClient client = new WebClient();
client.Credentials = new NetworkCredential("username", "password");
client.DownloadFile(
    "ftp://ftp.example.com/remote/path/file.zip", @"C:\local\path\file.zip");

如果您需要更大的控制，而WebClient 不提供（如TLS/SSL encryption、ascii/文本传输模式、resuming transfers 等），请使用FtpWebRequest。简单的方法是使用 Stream.CopyTo 将 FTP 响应流复制到 FileStream：

FtpWebRequest request =
    (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.DownloadFile;

using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(@"C:\local\path\file.zip"))
{
    ftpStream.CopyTo(fileStream);
}

如果你需要监控一个下载进度，你必须自己分块复制内容：

FtpWebRequest request =
    (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.DownloadFile;

using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(@"C:\local\path\file.zip"))
{
    byte[] buffer = new byte[10240];
    int read;
    while ((read = ftpStream.Read(buffer, 0, buffer.Length)) > 0)
    {
        fileStream.Write(buffer, 0, read);
        Console.WriteLine("Downloaded {0} bytes", fileStream.Position);
    }
}

有关 GUI 进度 (WinForms ProgressBar)，请参阅：
FtpWebRequest FTP download with ProgressBar

如果您想从远程文件夹下载所有文件，请参阅
C# Download all files and subdirectories through FTP。