ftpwebrequest下载文件
-
03-10-2019 - |
题
以下代码旨在通过FTP检索文件。但是,我遇到了一个错误。
serverPath = "ftp://x.x.x.x/tmp/myfile.txt";
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverPath);
request.KeepAlive = true;
request.UsePassive = true;
request.UseBinary = true;
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.Credentials = new NetworkCredential(username, password);
// Read the file from the server & write to destination
using (FtpWebResponse response = (FtpWebResponse)request.GetResponse()) // Error here
using (Stream responseStream = response.GetResponseStream())
using (StreamReader reader = new StreamReader(responseStream))
using (StreamWriter destination = new StreamWriter(destinationFile))
{
destination.Write(reader.ReadToEnd());
destination.Flush();
}
错误是:
远程服务器返回了一个错误:(550)不可用的文件(例如,找不到文件,无访问)
该文件确实存在于远程计算机上,我可以手动执行此FTP(即我有权限)。谁能告诉我为什么我可能会遇到这个错误?
解决方案
本段从 fptwebrequest类参考 您可能会感兴趣:
URI可能是相对的或绝对的。如果URI是形式的”ftp://contoso.com/%2FPath“(%2F是一个逃脱的' /'),然后URI是绝对的,并且当前目录为 /路径。但是,如果URI是形式的”ftp://contoso.com/path“首先,.NET框架将登录到FTP服务器(使用凭据属性设置的用户名和密码),然后将当前目录设置为 /路径。
其他提示
我知道这是一篇古老的帖子,但我在这里添加了以后的参考。这是我发现的解决方案:
private void DownloadFileFTP()
{
string inputfilepath = @"C:\Temp\FileName.exe";
string ftphost = "xxx.xx.x.xxx";
string ftpfilepath = "/Updater/Dir1/FileName.exe";
string ftpfullpath = "ftp://" + ftphost + ftpfilepath;
using (WebClient request = new WebClient())
{
request.Credentials = new NetworkCredential("UserName", "P@55w0rd");
byte[] fileData = request.DownloadData(ftpfullpath);
using (FileStream file = File.Create(inputfilepath))
{
file.Write(fileData, 0, fileData.Length);
file.Close();
}
MessageBox.Show("Download Complete");
}
}
根据Ilya Kogan的出色建议更新
最简单的方法
使用.NET Framework从FTP服务器下载二进制文件的最微不足道的方法是使用 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");
高级选项
采用 FtpWebRequest
, ,只有当您需要更大的控制权时 WebClient
不提供 TLS/SSL加密, ,进度监控等)。简单的方法就是将FTP响应流复制到 FileStream
使用 Stream.CopyTo
:
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);
}
进度监控
如果您需要监视下载进度,则必须自己复制内容:
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);
}
}
为GUI进度(Winforms ProgressBar
), 看:
ftpwebrequest ftp with progressbar下载
下载文件夹
如果要从远程文件夹下载所有文件,请参见
C#通过FTP下载所有文件和子目录.
我遇到过同样的问题!
我的解决方案是插入 public_html
文件夹到下载URL中。
服务器上的真实文件位置:
myhost.com/public_html/myimages/image.png
Web URL:
www.myhost.com/myimages/image.png
private static DataTable ReadFTP_CSV()
{
String ftpserver = "ftp://servername/ImportData/xxxx.csv";
FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpserver));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream responseStream = response.GetResponseStream();
// use the stream to read file from FTP
StreamReader sr = new StreamReader(responseStream);
DataTable dt_csvFile = new DataTable();
#region Code
//Add Code Here To Loop txt or CSV file
#endregion
return dt_csvFile;
}
我希望它能为您提供帮助。
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverPath);
此后,您可以使用以下行避免错误。(访问被拒绝等)
request.Proxy = null;
public void download(string remoteFile, string localFile)
{
private string host = "yourhost";
private string user = "username";
private string pass = "passwd";
private FtpWebRequest ftpRequest = null;
private FtpWebResponse ftpResponse = null;
private Stream ftpStream = null;
private int bufferSize = 2048;
try
{
ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + remoteFile);
ftpRequest.Credentials = new NetworkCredential(user, pass);
ftpRequest.UseBinary = true;
ftpRequest.UsePassive = true;
ftpRequest.KeepAlive = true;
ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;
ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
ftpStream = ftpResponse.GetResponseStream();
FileStream localFileStream = new FileStream(localFile, FileMode.Create);
byte[] byteBuffer = new byte[bufferSize];
int bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
try
{
while (bytesRead > 0)
{
localFileStream.Write(byteBuffer, 0, bytesRead);
bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
}
}
catch (Exception) { }
localFileStream.Close();
ftpStream.Close();
ftpResponse.Close();
ftpRequest = null;
}
catch (Exception) { }
return;
}