Withevents for dynamicly created controls

David Hovey

Hi there! I need some help with events for dynamicly created objects. The code below illustrates the problem. My situation will be a little different since the objects I will be dynamicly creating will be custom, but the problem is the same. The event will only fire on the last created object. How can I have an event fired within the form Class each time an individual instance of the label is clicked??

Public Class Form1
Friend WithEvents lbl As Label
Private i As Integer

Private Sub Form1\_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    i = 1
End Sub

Private Sub Form1\_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseUp
    lbl = New Label

    lbl.Name = "lbl" & i
    lbl.Text = "Label " & i
    lbl.Location = e.Location
    lbl.AutoSize = True

    Me.Controls.Add(lbl)
    i += 1

End Sub

Private Sub lbl\_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbl.Click

    MsgBox(lbl.Text)

End Sub

End Class

Anshumas

you must read about delegates in .net....

Anshuman Singh

Dave Kreskowiak

This code won't work. You only have one label wired up with it. Basically, you can't use WithEvents on a class-level variable and expect this to work. Drop the "Friend WithEvents..." line completely. Your MouseUp code has to create the label and wire up the events itself. This way, every label you create will maintain event connections.

Private Sub Form1\_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseUp
    Dim lbl As New Label
    ' lbl.Name = "lbl" & i  ' Drop this line.  It's not necessary
    lbl.Text = "Label " & i
    lbl.Location = e.Location
    lbl.AutoSize = True
    AddHandler lbl.Click, AddressOf lbl\_Click
    Me.Controls.Add(lbl)
    i += 1
End Sub

and drop the "Handles lbl.Click" from the end of the Sub you defined.

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2006, 2007, 2008

David Hovey

Works great! thanks for your help.