Implemented download with progress

I remember that when I was just using it, webclient did look quite simple, but after implementation, the download of small files was complete.

Large files must be downloaded all the time.

Later, I found it and used WebRequest and WebResponse to download the file with a progress prompt ..
The following code is extracted from one of my software. Only the key part is described...
========================================================== ==================================
If (Downloading = false) // if no file is being downloaded
{
TempDown = CurrentFileName;
If (CurrentFileName = "") {TempDown = B ;}
WhichDown = 1;
System. Threading. Thread ApcThread2 = new System. Threading. Thread (new System. Threading. ThreadStart (DownFile ));
ApcThread2.Start ();

}
Else
{
MessageBox. Show ("sorry, the file is being downloaded.", "prompt", messageboxbuttons. OK, messageboxicon. information );
}
##################
In general, if no file is being downloaded, start a new thread... download the file... the code of the downfile function ....
In simple cases, no comments will be made.
========================================================== ============================================
// Download block #################################### ######################################## #########################
Private void downfile ()
{
If (tempdown! = "")
{

If (downloading = false) // if no file is downloaded
{
Long fb;
This. apc_status_1.Text = "connecting to" + TempDown;
Downloading = true;
Try
{
// ===== Try URL validity and initialize the download Interface
WebRequest myre = WebRequest. Create (TempDown );
WebResponse mwrite = myre. GetResponse ();
Fb = mwrite. ContentLength;
This. apc_status_1.Text = "connection successful... download started ..";
Pbar. Value = 0;
Pbar. Maximum = (int) fb;
Pbar. Visible = true;
This. ApcList. Height = 156;
// ==== Start download
WebClient wc = new WebClient ();
SaveFileDialog sf = new SaveFileDialog ();
Sf. Title = "select the file storage location ";
Filename = CurrentFileName;
Sf. FileName = filename. Substring (filename. LastIndexOf ("/") + 1, filename. Length-filename.LastIndexOf ("/")-1 );
Sf. ShowDialog (this );
Filename = sf. FileName;
If (filename! = "")
{
Stream srm = wc. OpenRead (TempDown );
StreamReader srmer = new StreamReader (srm );
Byte [] mbyte = new byte [fb];
Int allbyte = (int) mbyte. Length;
Int startbyte = 0;
While (fb> 0) // ################ read the file cyclically and display the progress .....
{
Application. DoEvents ();
Int m = srm. Read (mbyte, startbyte, allbyte );
If (m = 0) {break ;}
Startbyte + = m;
Allbyte-= m;
Pbar. Value + = m;
Int a1 = (int) startbyte/1024;
Int a2 = (int) fb/1024;
This. apc_status_1.Text = "connection successful .. start to download .. "+ a1.ToString () +"/"+ a2.ToString () +" KB "; // startbyte +"/"+ fb. toString ();
}

FileStream fs = new FileStream (filename, FileMode. OpenOrCreate );
Fs. Write (mbyte, 0, mbyte. Length );
Fs. Flush ();

Srm. Close ();
Srmer. Close ();
Fs. Close ();

This. apclist. Height = 170;
Pbar. Visible = false;
This. apc_status_1.text = "the file has been downloaded! ";
}

}
Catch (webexception exp) // if the address is invalid or the file cannot be found
{
MessageBox. Show (exp. message, "", messageboxbuttons. OK, messageboxicon. information );
}
Downloading = false;
}
Else
{
MessageBox. Show ("sorry, the file is being downloaded.", "", MessageBoxButtons. OK, MessageBoxIcon. Information );
}
}
Else
{
If (WhichDown = 1)
{
MessageBox. Show ("no file is currently played.", "", MessageBoxButtons. OK, MessageBoxIcon. Information );
}
Else
{
MessageBox. Show ("select the file you want to download from the list.", "", MessageBoxButtons. OK, MessageBoxIcon. Information );
}
}

}//