Activated event doesn't fire????

[bpayne111]

To keep it simple...

I have a form in an MDI app and i'd like to show a message box when it is activated. The activate event never fires when i load the child form. Is this because it's a child form? I think i've almost got it figured out but i'd like to hear any comments on the subject.

[divil]

I think the parent form has an MdiChildActivate event.

[bpayne111]

yes i was playing with that as i wrote the post... why would they do this? i don't get it. It seems impossible to get the 'true' activate event to fire no matter what i do.

[bpayne111]

could it be that there is just a bug in my version of vs.net? me and my teacher are playing with this and well basically you can't predict when the activate event is gonna fire. Sometimes it works sometimes it doesn't. I have version 1.0.3705 of the framework and i can't upgrade. Could this be my issue?

 

'frmMain
Dim frmTest as form 'modular variable

Private Sub ToolBar1_ButtonClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ToolBarButtonClickEventArgs) Handles ToolBar1.ButtonClick

       Select Case ToolBar1.Buttons.IndexOf(e.Button)
           Case 0
               'show frmKandles
               If FormLoaded("frmKandles") Then
                   frmTest.Activate()
               Else
                   frmTest = New frmKandles()
                   frmTest.MdiParent = Me
                   frmTest.Show()
               End If
           Case 1
               'show frmSummary
               If FormLoaded("frmSummary") Then
                   frmTest.Activate()
               Else
                   frmTest = New frmSummary()
                   frmTest.MdiParent = Me
                   frmTest.Show()
               End If
           Case 2
               'show frmAbout
               If FormLoaded("frmAbout") Then
                   frmTest.Activate()
               Else
                   frmTest = New frmAbout()
                   frmTest.MdiParent = Me
                   frmTest.Show()
               End If
       End Select
   End Sub

   Public Function FormLoaded(ByVal strName As String) As Boolean
       'check to see if form is loaded

       For Each frmTest In Me.MdiChildren
           If frmTest.Name = strName Then
               Return True
           End If
       Next
   End Function
 
Private Sub frmMain_MdiChildActivate(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.MdiChildActivate
       'work to be done
       If FormLoaded("frmSummary") Then
           frmTest.Activate()
       End If
   End Sub


'code in child form frmSummary
Private Sub frmSummary_Activated(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Activated
       MessageBox.Show("hey 2")
   End Sub

[Nerseus]

I have the same version of the framework (build 3705) and I have no trouble with the Activated event firing on the child form.

 

Here's what I did:

1. Create new C# winform project

2. Change Form1's IsMdiContainer property to true

3. Added a second form (Form2) and added an Activated event with a MessageBox.Show

3. Added a main menu and click event to Form1

4. In the click event I create a new instance of Form1, set it's MdiParent property to Form1 (I use "this"), and show the new form2.

 

I see the messagebox, no worries.

Maybe you could post a zip of your project and I could test it here, on my machine?

 

-nerseus

[bpayne111]

if you still have that project saved... try using 2 different child forms. And try getting the Activate event to fire anytime AFTER the first activate for that child form.

ie. Load both forms as children. Then click back and forth between them and see if it will fire then.

The activate event should fire each time the form 'recieves focus' correct?

 

I'll send the code in my next post if needed

Thanks

[divil]

No, not correct. The event you use to tell when Mdi Children are switched between is the MdiChildActivate event on the parent form.

[bpayne111]

how can you determine which child is activated?

[Nerseus]

Ah, didn't test my code far enough - only first the Activated event on the child form the first time the first instance is shown. Never fires again.

 

You can use the ActiveMdiChild property of the MDIParent form to get the active child form. Since you're accessing this in the MdiChildActivate event, it should be the one that's receiving focus. I tested with the following code and it worked like a charm. Of course, I only show Form2 as a child - if you have different child forms, you can't use the direct casting as I've done here.

 

private void Form1_MdiChildActivate(object sender, System.EventArgs e)
{
Form2 f = (Form2)this.ActiveMdiChild;
MessageBox.Show(f.Handle.ToInt32().ToString() + ": " + f.Text);
}

 

-Nerseus

[bpayne111]

thanks alot i figured it out now. that C# code kinda hurt my eyes but i made it through

 

thanks