I am writing a VB form application that redirects the standard output stream of a process and uses it in a UI.
I am having trouble calling methods with parameters that update controls on the form from the OutputHandler sub.
I can call a method without parameters like so
Me.Invoke(New MyDelSub(AddressOf ServerStarted))
Dim del As JoinDelegate = AddressOf PlayerJoins
del.Invoke(username)
Private Delegate Sub JoinDelegate(ByVal username As String)
Private Sub PlayerJoins(ByVal username As String)
PlayersBox.Items.Add(username)
'Do other stuff
End Sub
1) Supposing you have a method like this:
Public Sub DoSomething(value1 As String, value2 As String)
MessageBox.Show(String.Format("{0} {1}", value1, value2))
End Sub
You can call it using invoke this way:
Me.Invoke(Sub() DoSomething("Hello", "World!"))
2) If you want to make thread safe call to a control you can write the method this way:
Public Sub AddItemToListBox1(item As String)
If (ListBox1.InvokeRequired) Then
ListBox1.Invoke(Sub() AddItemToListBox1(item))
Else
ListBox1.Items.Add(item)
End If
End Sub
Then it's enough to call it in a the UI thread or in another thread the same way simply:
AddItemToListBox1("some item")
The call would be thread safe.