使用ftpwebrequest下载文件时遇到问题 [英] facing an issue while downloading file using ftpwebrequest
本文介绍了使用ftpwebrequest下载文件时遇到问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
如果我尝试下载小于10MB的文件，我在使用ftp下载文件时遇到了问题，但是可以，但是如果我下载12MB的文件，它将下载到100％，并且它
引发Web异常:基础连接已关闭:接收时发生意外错误"
在关闭流之后，文件已正确下载到磁盘上！
我使用许多工具下载了此文件，一切都很好
我很久以前一直在搜索，但我发现了非常不错的结果，但是猜到了什么..对于指定的情况没有答案，他们已经回答了有关wcf，web服务等的问题
代码:
i have been facing an issue while downloading file using ftp if i try to download files less than 10MB it''s ok but if i download a 12MB file it downloads it till 100% and it
throw Web Exception : "The underlying connection was closed: An unexpected error occurred on a receive"
and after closing streams the file is downloaded correctly on disk !!
i downloaded this file with many tools and it''s fine
i have been searching for a long time ago and i found a very huge results about this but guess what .. no answers for the specified case they have answered questions about wcf , web services , etc
Code :
private void FtpDownloadFile(string fileDirectory, string fileName)
{
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftpServerIP + "/" + fileName);
request.Method = WebRequestMethods.Ftp.GetFileSize;
request.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = true;
//request.EnableSsl = true;
intFileSize = request.GetResponse().ContentLength;
intRunningByteTotal = 0;
request.ContentLength = intFileSize;
request = (FtpWebRequest)FtpWebRequest.Create(ftpServerIP + "/" + fileName);
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.Credentials = new NetworkCredential(ftpUserID,
ftpPassword);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
//request.EnableSsl = true;
request.ReadWriteTimeout = 10000000;
response = (FtpWebResponse)request.GetResponse();
reader = response.GetResponseStream();
writer = new FileStream(fileDirectory + "\\" + fileName, FileMode.Create, FileAccess.Write, FileShare.None);
byte[] byteBuffer = new byte[1024];
int intByteSize = 0;
int intProgressPct = 0;
while ((intByteSize = reader.Read(byteBuffer, 0, byteBuffer.Length)) > 0)
{
try
{
if (intByteSize == 0)
{
intProgressPct = 100;
FtpDownloadBackground.ReportProgress(intProgressPct);
}
else
{
if (reader != null)
{
writer.Write(byteBuffer, 0, intByteSize);
}
if (intByteSize + intRunningByteTotal <= intFileSize)
{
intRunningByteTotal += intByteSize;
double dIndex = intRunningByteTotal;
double dTotal = byteBuffer.Length;
double dProgressPct = 100.0 * intRunningByteTotal / intFileSize;
intProgressPct = (int)dProgressPct;
totalPercentage = (int)((nDownloadedTotal + intRunningByteTotal) * 100 / totalsize);
//------------------------------
FtpDownloadBackground.ReportProgress(intProgressPct);
}
}
}
catch (Exception e)
{
}
}
nDownloadedTotal += intFileSize;
//------------------------
}
catch (WebException ex)
{
//Web Exception : "The underlying connection was closed: An unexpected error occurred on a receive"
}
catch (Exception ex)
{
//MessageBox.Show(ex.ToString());
}
finally
{
if (reader != null)
{
reader.Close();
}
if (response != null)
{
response.Close();
}
if (writer != null)
{
writer.Close();
}
}
}
在此先感谢
thanks in advance
推荐答案
您可以尝试...
You Can Try This...
public static bool DownloadFromFTP_FTPS(string remoteFilePath, string localFilePath,string UserId,string Password, out string error)
{
error = string.Empty;
try
{
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(HostName.TrimEnd(new char[] { '/' }) + "//" + remoteFilePath);
//request.EnableSsl = true;
request.Credentials = new NetworkCredential(UserId, Password);
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.UseBinary = true;
// read file into byte array
StreamWriter requestStream = new StreamWriter(localFilePath);
Stream sourceStream = request.GetResponse().GetResponseStream();
byte[] bit = new byte[4096];
int intSt = sourceStream.Read(bit, 0, bit.Length);
while (intSt > 0)
{
requestStream.BaseStream.Write(bit, 0, intSt);
intSt = sourceStream.Read(bit, 0, bit.Length);
}
sourceStream.Dispose();
requestStream.Dispose();
requestStream.Close();
sourceStream.Close();
return true;
}
catch (Exception ex)
{
error = ex.Message;
return false;
}
}
您可以异步下载文件...
参考:单击此处
Hi,
You can download file Asynchronously...
Reference : Click Here
using System;
using System.Net;
using System.Threading;
using System.IO;
namespace Examples.System.Net
{
public class FtpState
{
private ManualResetEvent wait;
private FtpWebRequest request;
private string fileName;
private Exception operationException = null;
string status;
public FtpState()
{
wait = new ManualResetEvent(false);
}
public ManualResetEvent OperationComplete
{
get {return wait;}
}
public FtpWebRequest Request
{
get {return request;}
set {request = value;}
}
public string FileName
{
get {return fileName;}
set {fileName = value;}
}
public Exception OperationException
{
get {return operationException;}
set {operationException = value;}
}
public string StatusDescription
{
get {return status;}
set {status = value;}
}
}
public class AsynchronousFtpUpLoader
{
// Command line arguments are two strings:
// 1. The url that is the name of the file being uploaded to the server.
// 2. The name of the file on the local machine.
//
public static void Main(string[] args)
{
// Create a Uri instance with the specified URI string.
// If the URI is not correctly formed, the Uri constructor
// will throw an exception.
ManualResetEvent waitObject;
Uri target = new Uri (args[0]);
string fileName = args[1];
FtpState state = new FtpState();
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(target);
request.Method = WebRequestMethods.Ftp.UploadFile;
// This example uses anonymous logon.
// The request is anonymous by default; the credential does not have to be specified.
// The example specifies the credential only to
// control how actions are logged on the server.
request.Credentials = new NetworkCredential ("anonymous","janeDoe@contoso.com");
// Store the request in the object that we pass into the
// asynchronous operations.
state.Request = request;
state.FileName = fileName;
// Get the event to wait on.
waitObject = state.OperationComplete;
// Asynchronously get the stream for the file contents.
request.BeginGetRequestStream(
new AsyncCallback (EndGetStreamCallback),
state
);
// Block the current thread until all operations are complete.
waitObject.WaitOne();
// The operations either completed or threw an exception.
if (state.OperationException != null)
{
throw state.OperationException;
}
else
{
Console.WriteLine("The operation completed - {0}", state.StatusDescription);
}
}
private static void EndGetStreamCallback(IAsyncResult ar)
{
FtpState state = (FtpState) ar.AsyncState;
Stream requestStream = null;
// End the asynchronous call to get the request stream.
try
{
requestStream = state.Request.EndGetRequestStream(ar);
// Copy the file contents to the request stream.
const int bufferLength = 2048;
byte[] buffer = new byte[bufferLength];
int count = 0;
int readBytes = 0;
FileStream stream = File.OpenRead(state.FileName);
do
{
readBytes = stream.Read(buffer, 0, bufferLength);
requestStream.Write(buffer, 0, readBytes);
count += readBytes;
}
while (readBytes != 0);
Console.WriteLine ("Writing {0} bytes to the stream.", count);
// IMPORTANT: Close the request stream before sending the request.
requestStream.Close();
// Asynchronously get the response to the upload request.
state.Request.BeginGetResponse(
new AsyncCallback (EndGetResponseCallback),
state
);
}
// Return exceptions to the main application thread.
catch (Exception e)
{
Console.WriteLine("Could not get the request stream.");
state.OperationException = e;
state.OperationComplete.Set();
return;
}
}
// The EndGetResponseCallback method
// completes a call to BeginGetResponse.
private static void EndGetResponseCallback(IAsyncResult ar)
{
FtpState state = (FtpState) ar.AsyncState;
FtpWebResponse response = null;
try
{
response = (FtpWebResponse) state.Request.EndGetResponse(ar);
response.Close();
state.StatusDescription = response.StatusDescription;
// Signal the main application thread that
// the operation is complete.
state.OperationComplete.Set();
}
// Return exceptions to the main application thread.
catch (Exception e)
{
Console.WriteLine ("Error getting response.");
state.OperationException = e;
state.OperationComplete.Set();
}
}
}
}
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