WPF : Accessing a UI object with a Thread gives an error

Question

I have a function that is called when a file is modified in a folder. This function updates the items of a listview which is stored in the UI.

Here is the function :

Private Sub FileChangeNotify()
    Try
        LstMoulures.Items.Refresh()
    Catch ex As Exception
        MsgBox(Ex.exception)
    End Try

End Sub

Here is the error: "Le thread appelant ne peut pas accéder à cet objet parce qu'un autre thread en est propriétaire." (Translation : The calling thread cannot access this object because it is owned by another thread)

Thanks.

score 3 · Answer 1 · edited May 23 '17 at 10:33

3

You cannot modify objects in the UI thread directly from another thread - check out the BeginInvoke method, which lets you access UI objects across threads.

Check out WPF C# - Editing a listbox from another thread

edited May 23 '17 at 10:33

Community

1
1

answered Jul 05 '11 at 15:59

Nick B

1,093
9
19

score 1 · Accepted Answer · answered Jul 05 '11 at 16:02

1

Private Sub FileChangeNotify()
  LstMoulures.Dispatcher.BeginInvoke (New Action(AddressOf LstMoulures.Items.Refresh))
End Sub

answered Jul 05 '11 at 16:02

agent-j

26,389
5
49
78

WPF : Accessing a UI object with a Thread gives an error

2 Answers2