在C#/ .NET中上传和下载二进制文件到/从FTP服务器下载

时间:2017-06-17 14:58:29

标签: c# .net ftp webclient ftpwebrequest

我正在使用.NET 4 C#。我正在尝试上传然后将ZIP文件下载到(我的)服务器。

上传时我有

using (WebClient client = new WebClient())
{
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(MyUrl);
    request.Method = WebRequestMethods.Ftp.UploadFile;
    request.EnableSsl = false;
    request.Credentials = new NetworkCredential(MyLogin, MyPassword);
    byte[] fileContents = null;
    using (StreamReader sourceStream = new StreamReader(LocalFilePath))
    {
        fileContents = Encoding.UTF8.GetBytes(sourceStream.ReadToEnd());
    }
    request.ContentLength = fileContents.Length;
    using (Stream requestStream = request.GetRequestStream())
    {
        requestStream.Write(fileContents, 0, fileContents.Length);
    }
    FtpWebResponse response = null;
    response = (FtpWebResponse)request.GetResponse();
    response.Close();
}

这似乎有效,因为我在服务器上获得了正确大小的文件。

1)如何流式传输,而不是先将其加载到内存中?我将上传非常大的文件。

下载我有

using (WebClient client = new WebClient())
{
    string HtmlResult = String.Empty;
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(remoteFile);
    request.Method = WebRequestMethods.Ftp.DownloadFile;
    request.EnableSsl = false;
    request.Credentials = new NetworkCredential(MyLogin, MyPassword);
    using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
    using (Stream responseStream = response.GetResponseStream())
    using (StreamReader reader = new StreamReader(responseStream))
    using (FileStream writer = new FileStream(localFilename, FileMode.Create))
    {
        long length = response.ContentLength;
        int bufferSize = 2048;
        int readCount;
        byte[] buffer = new byte[2048];
        readCount = responseStream.Read(buffer, 0, bufferSize);
        while (readCount > 0)
        {
            writer.Write(buffer, 0, readCount);
            readCount = responseStream.Read(buffer, 0, bufferSize);
        }
    }
}

2)一切似乎都有效...除非我尝试解压缩下载的ZIP文件,否则会收到无效的ZIP文件。

1 个答案:

答案 0 :(得分:10)

上传

使用.NET框架将二进制文件上传到FTP服务器的最简单方法是使用WebClient.UploadFile

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");

如果您需要更强的控件,WebClient不提供(如TLS / SSL加密等),请使用FtpWebRequest。简单的方法是使用Stream.CopyToFileStream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);
}

如果您需要监控上传进度,则必须自行复制内容:

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);
    } 
}

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

如果要上传文件夹中的所有文件,请参阅
Upload directory of files using WebClient

下载

使用.NET框架从FTP服务器下载二进制文件的最简单方法是使用WebClient.DownloadFile

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");

如果您需要更强的控件,WebClient不提供(如TLS / SSL加密等),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);
}

如果您需要监控下载进度,则必须自行复制内容:

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);
    }
}

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

如果要从远程文件夹下载所有文件,请参阅
C# Download all files and subdirectories through FTP