Re: how can recognize file extension for download - C# Discussion Boards

3-Feb-07 4:06

hello

i wanto create an application (C#) like "free download manager" for download files.
i use "System.Net.WebClient" class for this .
such as following
...
string filename
System.Net.WebClient client = new System.Net.WebClient();
....
try
{
Uri uri = new Uri(urlTextBox.Text);
string fileName = System.IO.Path.GetFileName(urlTextBox.Text);

string downloadString = client.DownloadString(uri);
this.toolStripProgressBar1.Value = 0;
client.DownloadFileAsync(uri, fileName);
this.downloadButton.Text = "Cancel";
isBusy = true;
}
catch (UriFormatException ex)
{
MessageBox.Show(ex.Message);
}
...

my problem in use of this class is, i don't know how recognize file extension (in my code "fileName" vaiable) to download like .txt, .pdf

Rizawn3-Feb-07 4:33

3-Feb-07 4:33

hi
you can verify the url when the Download url is entered in the textBox like

[CODE]

string s="http://www.google.com/file.txt";
if(s.EndsWith(".pdf")||s.EndsWith(".exe")))
{
//call the function for file download
}
else
//error message

[/CODE]

Q@!$3r

B.A3-Feb-07 5:24

3-Feb-07 5:24

string fileExtention = System.IO.Path.GetExtension(urlTextBox.Text);

Rizawn4-Feb-07 1:16

4-Feb-07 1:16

hmm just wondering how to check if the download url is like this..

http://www.some-site.com/sessionid/file?get=74

Like many site don't provide direct download link to prevent leeching ...

Q@!$3r

B.A4-Feb-07 3:50

4-Feb-07 3:50

yes
my problem is this Confused | :confused:

WebClient And ProgressBar

VirtualVoid.NET6-Feb-07 3:53

VirtualVoid.NET

6-Feb-07 3:53

hmm, try send WebRequest to url like this, and watch what the WebResponse is doing (or maybe the WebResponse's stream).. or create function to handle redirections, which MUST come from the WebResponse...

VirtualVoid.NET

Thread confusion !!

Hussam Fattahi3-Feb-07 3:30

Hussam Fattahi

3-Feb-07 3:30

i have a multi threaded program, and i'm confused about how thread works.

well, my question is that if i create a new thread, it will run along with the thread
of the main program, and if i call any function form within the new thread that i create, it will be excuted in the new thread, but if i want to call an asynchronous
operation from the new thread, what will happen then(since any asynchronous operation
will create new thread), it will be a thread inside thread or what?

i just need a little illustration a bout this situation.

Re: Thread confusion !!

Guffa3-Feb-07 3:57

Guffa

3-Feb-07 3:57

Threads are not inside each other, threads are inside the application. If you start a new thread, it will be inside the same application, not inside any other thread.

---
single minded; short sighted; long gone;

Rizawn3-Feb-07 2:52

Re: WebClient And ProgressBar

3-Feb-07 2:52

Hi,

I am using the following method to download a file from the internet ;

WebClient.DownloadFile(url,file_name_to_save)

Is it possible to show the progress of Download in a ProgressBar? I know it can be done via WebRequest and WebResponse object..But can it be done with WebClient Object?

Regards

Q@!$3r

B.A3-Feb-07 4:12

Re: WebClient And ProgressBar

3-Feb-07 4:12

hi , you can use this code ...
but befor i put code , i have a question :
for download , how can recognize the file extention ?

--------------------------------------------------------------
you can use "Download Progress Indicator Technology Sample "
topic in msdn

--------------------------------------------------------------
code
--------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.IO;

namespace downloadManager
{
public partial class Form1 : Form
{
private bool isBusy;
private WebClient client;

public Form1()
{
InitializeComponent();
client = new WebClient();

// Wire up the download complete event handler.
// The operation will either complete successfully or with an
// error code.
client.DownloadFileCompleted += client_DownloadFileCompleted;
// Wire up the download progress event handler.
client.DownloadProgressChanged += client_DownloadProgressChanged;
}

private void button1_Click(object sender, EventArgs e)
{
// If an operation is pending, then the user has clicked cancel.
if (isBusy)
{
client.CancelAsync();
isBusy = false;
this.downloadButton.Text = "Download";
}
// Otherwise go ahead and start the download
else
{
try
{
Uri uri = new Uri(urlTextBox.Text);
string fileName = System.IO.Path.GetFileName(urlTextBox.Text);
string fileExtention = System.IO.Path.GetExtension(urlTextBox.Text);
string downloadString = client.DownloadString(uri);
this.toolStripProgressBar1.Value = 0;
client.DownloadFileAsync(uri, "test");
this.downloadButton.Text = "Cancel";
isBusy = true;
}
catch (UriFormatException ex)
{
MessageBox.Show(ex.Message);
}
}
}

// Displays a message indicating that the download completed
// successfully, or if there was an error it will be displayed instead.
private void client_DownloadFileCompleted(
object sender, AsyncCompletedEventArgs e)
{
isBusy = false;
this.downloadButton.Text = "Download";
if (e.Error == null)
{
MessageBox.Show("Download Complete");
}
else
MessageBox.Show("Download Not Complete: " + e.Error.Message);
this.toolStripProgressBar1.Value = 0;
}

// Updates the progress indicator with the latest progress
private void client_DownloadProgressChanged(
object sender, DownloadProgressChangedEventArgs e)
{
this.toolStripProgressBar1.Value = e.ProgressPercentage;
}

}
}

Rizawn3-Feb-07 4:26