Daniel André Daniel André - 28 days ago 7x
C# Question

How do I detect average download speed?

So I want to make an Speedtest alike, I am downloading an 100MB file (is it too much to test average download speed?).
I am getting an huge number and I can't calculate the average download speed like that...

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If Downloading Then Exit Sub
Downloading = True

Dim wc As New WebClient
AddHandler wc.DownloadProgressChanged, AddressOf wc_ProgressChanged
AddHandler wc.DownloadFileCompleted, AddressOf wc_DownloadDone

wc.DownloadFileAsync(New Uri("http://speedtest.ftp.otenet.gr/files/test100Mb.db"), tmp, Stopwatch.StartNew)
End Sub

Private Sub wc_DownloadDone(sender As Object, e As System.ComponentModel.AsyncCompletedEventArgs)
Downloading = False
End Sub

Private Sub wc_ProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs)
Me.Label2.Text = (e.BytesReceived / (DirectCast(e.UserState, Stopwatch).ElapsedMilliseconds / 1000.0#)).ToString("#")
End Sub

Offtopic: Is there also a way to calculate the average upload speed?


The huge number you are getting is bytes/second. You need to divide it by 1024 to get Kilobytes/second or (1024 * 1024) to get Megabytes/second

Me.Label2.Text = (e.BytesReceived / (DirectCast(e.UserState, Stopwatch).ElapsedMilliseconds / 1000.0#) / (1024 * 1024)).ToString("#")

To get Megabits per second like speed test does you need to also multiply by 8

Me.Label2.Text = (e.BytesReceived / (DirectCast(e.UserState, Stopwatch).ElapsedMilliseconds / 1000.0#) / (1024 * 1024) * 8).ToString("#")