CODEWITHSUNDEEP
vb.netlistbox
Andy Visser
Andy Visser

Reputation: 95

Can't add an item to a listbox

I get an error about cross-threading when I try to add an item to a listbox. This Sub is located inside the frmMain class. lstSells is a listbox on frmMain. Its gotta be a simple fix but 20+ goods searches later and tons of web pages I'm not seeing it. People say they have problems when trying to do it from a different class, but not like this. I am fairly new to vb.net, used to us VB6 a fair bit, so maybe it's something simple I'm missing here?

Private Sub OnMessage(sender As Object, e As MessageEventArgs)

    Messages.Add(e.Data)

    lstSells.Items.Add("test")

End Sub

Upvotes: 0

Views: 1406

Answers (2)

T30
T30

Reputation: 12222

The problem fires when you try to update the form from another Thread, not necessary from another class.

See how to call delegates on MSDN, they really helps! http://msdn.microsoft.com/en-us/library/zyzhdc6b.aspx

Upvotes: 2

ElektroStudios
ElektroStudios

Reputation: 20464

Try this:

    If lstSells.InvokeRequired Then
        lstSells.Invoke(Sub() lstSells.Items.Add("test"))
    Else
        lstSells.Items.Add("test")
    End If

Upvotes: 1

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