问题
My code works, but the ProgressBar jumps directly to 100% and the download will go on. When its finished then comes a messageBox to take a Info.
I have already changed the buffer size, but it doesn't matter.
What am I doing wrong here?
Here is my Code:
void workerDOWN_DoWork(object sender, DoWorkEventArgs e)
{
string fileFullPath = e.Argument as String;
string fileName = Path.GetFileName(fileFullPath);
string fileExtension = Path.GetExtension(fileName);
label4.Invoke((MethodInvoker)delegate { label4.Text = "Downloading File.."; });
string ftpServerIP = "XXX";
string ftpUserName = "XXX";
string ftpPassword = "XXX";
try
{
//Datei vom FTP Server downloaden
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://" + ftpServerIP + "/" + fileName);
request.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
request.Method = WebRequestMethods.Ftp.DownloadFile;
using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(fileFullPath))
{
var buffer = new byte[32 * 1024];
int totalReadBytesCount = 0;
int readBytesCount;
while ((readBytesCount = ftpStream.Read(buffer, 0, buffer.Length)) > 0)
{
fileStream.Write(buffer, 0, readBytesCount);
totalReadBytesCount += readBytesCount;
var progress = (int)((float)totalReadBytesCount / (float)fileStream.Length * 100);
workerDOWN.ReportProgress((int)progress);
label3.Invoke((MethodInvoker)delegate { label3.Text = progress + " %"; });
}
}
}
catch (WebException ex)
{
FtpWebResponse response = (FtpWebResponse)ex.Response;
if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
{
MessageBox.Show("Datei nicht gefunden!", "Error");
}
}
e.Result = fileFullPath;
}
void workerDOWN_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
string fileFullPath = e.Result as String;
string fileName = Path.GetFileName(fileFullPath);
MessageBox.Show("Download erfolgreich!","Information");
progressBar1.Value = 0;
label3.Invoke((MethodInvoker)delegate { label3.Text = " "; });
label4.Invoke((MethodInvoker)delegate { label4.Text = " "; });
}
回答1:
Trivial example of FTP download using FtpWebRequest with WinForms progress bar:
private void button1_Click(object sender, EventArgs e)
{
// Run Download on background thread
Task.Run(() => Download());
}
private void Download()
{
try
{
const string url = "ftp://ftp.example.com/remote/path/file.zip";
NetworkCredential credentials = new NetworkCredential("username", "password");
// Query size of the file to be downloaded
WebRequest sizeRequest = WebRequest.Create(url);
sizeRequest.Credentials = credentials;
sizeRequest.Method = WebRequestMethods.Ftp.GetFileSize;
int size = (int)sizeRequest.GetResponse().ContentLength;
progressBar1.Invoke(
(MethodInvoker)(() => progressBar1.Maximum = size));
// Download the file
WebRequest request = WebRequest.Create(url);
request.Credentials = credentials;
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);
int position = (int)fileStream.Position;
progressBar1.Invoke(
(MethodInvoker)(() => progressBar1.Value = position));
}
}
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
The core download code is based on:
Upload and download a binary file to/from FTP server in C#/.NET
To explain why your code does not work:
- You are using size of the target file for the calculation:
fileStream.Length- It will always be equal tototalReadBytesCount, hence theprogresswill always be 100. - You probably meant to use
ftpStream.Length, but that cannot be read. - Basically with FTP protocol, you do not know size of the file you are downloading. If you need to know it, you have to query it explicitly before the download. Here I use the
WebRequestMethods.Ftp.GetFileSizefor that.
回答2:
Without knowing exactly what your code in the ProgressChanged eventhandler does, I think that you unintentionally put the brackets in your progress calculation after * 100.
You could try this:
var progress = (int)((float)totalReadBytesCount / (float)fileStream.Length) * 100;
回答3:
i have now a solution thats work for me.
The Idea to get first the File Size was great. But when i first makes an query to check the File Size, the Ftp Server throws a Error. Like this FtpWebRequest error: 550 Size not allowed in ASCII mode
Now first i download a dummy file to open the Connection.. See below
Thanks to all for the Support.
Great Community. Thanks.
void workerDOWN_DoWork(object sender, DoWorkEventArgs e)
{
string fileFullPath = e.Argument as String;
string fileName = Path.GetFileName(fileFullPath);
string fileExtension = Path.GetExtension(fileName);
label4.Invoke((MethodInvoker)delegate { label4.Text = "Downloading File.."; });
//FTP Download und Delete
string ftpServerIP = "XXX";
string ftpUserName = "XXXX";
string ftpPassword = "XXXXX";
try
{
// dummy download ftp connection for ftp server bug
FtpWebRequest DummyRequest = (FtpWebRequest)WebRequest.Create(("ftp://" + ftpServerIP + "/anyfile"));
DummyRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
DummyRequest.Method = WebRequestMethods.Ftp.DownloadFile;
using (Stream ftpStream = DummyRequest.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(Path.GetDirectoryName(Application.ExecutablePath) + "\\anyfile"))
{
ftpStream.CopyTo(fileStream);
}
//delete downloaded test file
File.Delete(Path.GetDirectoryName(Application.ExecutablePath) + "\\anyfile");
// Query size of the file to be downloaded
FtpWebRequest sizeRequest = (FtpWebRequest)WebRequest.Create("ftp://" + ftpServerIP + "/" + fileName);
sizeRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
sizeRequest.Method = WebRequestMethods.Ftp.GetFileSize;
var fileSize = sizeRequest.GetResponse().ContentLength;
//file download
FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://" + ftpServerIP + "/" + fileName);
request.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
request.Method = WebRequestMethods.Ftp.DownloadFile;
using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(fileFullPath))
{
var buffer = new byte[32 * 1024];
int totalReadBytesCount = 0;
int readBytesCount;
while ((readBytesCount = ftpStream.Read(buffer, 0, buffer.Length)) > 0)
{
fileStream.Write(buffer, 0, readBytesCount);
totalReadBytesCount += readBytesCount;
var progress = (int)((float)totalReadBytesCount / (float)fileSize * 100);
workerDOWN.ReportProgress((int)progress);
label3.Invoke((MethodInvoker)delegate { label3.Text = progress + " %"; });
}
}
// delete file on ftp server
FtpWebRequest Delrequest = (FtpWebRequest)WebRequest.Create("ftp://" + ftpServerIP + "/" + fileName);
Delrequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);
Delrequest.Method = WebRequestMethods.Ftp.DeleteFile;
FtpWebResponse Delresponse = (FtpWebResponse)Delrequest.GetResponse();
Delresponse.Close();
// message file deleted
richTextBox1.Invoke((MethodInvoker)delegate { richTextBox1.AppendText("System: " + fileName + " wurde auf dem Server gelöscht." + Environment.NewLine); });
}
catch (WebException ex)
{
FtpWebResponse response = (FtpWebResponse)ex.Response;
if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
{
MessageBox.Show("Datei nicht gefunden!", "Error");
}
}
e.Result = fileFullPath;
}
void workerDOWN_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
void workerDOWN_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
string fileFullPath = e.Result as String;
string fileName = Path.GetFileName(fileFullPath);
MessageBox.Show("Download erfolgreich!","Information");
progressBar1.Value = 0;
label3.Invoke((MethodInvoker)delegate { label3.Text = " "; });
label4.Invoke((MethodInvoker)delegate { label4.Text = " "; });
}
来源：https://stackoverflow.com/questions/45269263/ftpwebrequest-ftp-download-with-progressbar