Backgroundworker and my.computer.network.ping

Can you post the code you are using? I tried just this and it worked fine.

Are you calling Ping in the DoWork handler?

Just as I suspected. You are calling Ping on the UI thread.

The line:

If lvPcs.InvokeRequired Then lvPcs.Invoke(New getpcnummerdelegate(AddressOf getpcnummer), New Object() {i})

It is basically saying; 'if not on the user interface thread, then call this method on the user interface thread'. Which defeats the purpose of having the background worker in the first place.

I would probably do something like this:

Imports System.Net.NetworkInformation Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim urls(ListView1.Items.Count - 1) As String For i As Integer = 0 To ListView1.Items.Count - 1 urls(i) = ListView1.Items(i).Text Next BackgroundWorker1.RunWorkerAsync(urls) End Sub Private Sub OnBackgroundWorkerDoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork Dim urls() = CType(e.Argument, String()) For i As Integer = 0 To urls.Length - 1 Dim success As Boolean = False Try success = My.Computer.Network.Ping(urls(i)) Catch ex As PingException Catch ex As InvalidOperationException End Try BackgroundWorker1.ReportProgress(i, success) Next End Sub Private Sub OnBackgroundWorkerProgressChanged(ByVal sender As System.Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged If e.UserState = True Then ListView1.Items(e.ProgressPercentage).ImageIndex = 0 Else ListView1.Items(e.ProgressPercentage).ImageIndex = 1 End If End Sub End Class

This assumes that you have:

1. A Button control named Button1
2. A ListView control named ListView1
3. A BackgroundWorker component named BackgroundWorker1