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[.NET] Tab not disposing - Printable Version

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+---- Thread: [.NET] Tab not disposing (/showthread.php?tid=4983540)

Tab not disposing - Josh‎ - Sep 11, 2015

Hi all,

I have a tab control which a user can dynamically add tabs and remove tabs.
The tabs contain controls that use up resources (specifically a connect to a SQL DB and numerous table adapters). Naturally, when a tab is opened, the processor and memory usage goes up. The issue is when the tab is closed, the usage doesn't drop again. Any idea what causes this?

Thanks, Josh

* - Odus - Sep 11, 2015

First thing that comes to mind is to loop through and dispose all child controls on the tab page to be closed, then get rid of it.

* - aleeeeeee - Sep 11, 2015

or create control in runtime:
example
Code
//tab control event
public override void OnControlAdded(args blalba)
{
  if (e.Control is TabPage)
{
   var page = e.Control as tabpage;
   using (var button = new button() { //here properties like location and size})
    {
      button.Click += (sender,args) => //sql connection;
page.Controls.Add(button);
    }
//using dispos object automatically
}

}

i haven't tried it on visual studio

* - Josh‎ - Sep 11, 2015

(Sep 11, 2015 06:44 AM)Odus Wrote:  First thing that comes to mind is to loop through and dispose all child controls on the tab page to be closed, then get rid of it.

I do this:

Code
Private Sub disposeControls(ByVal c As Control)
      If c.Controls.Count > 0 Then
      For Each ctrl As Control In c.Controls
            disposeControls(ctrl)
      Next
      End If
      c.Dispose()
    End Sub

And when I want to remove a tab I use:

Code
Dim tp As TabPage = 'Code to get the tab I want
disposeControls(tp)
TabControl1.TabPages.Remove(tp)


* - Odus - Sep 11, 2015

Don't forget to call Dispose on the TabPage itself. Also for your control arg, you can use HasChildren property:

Code
Private Sub DisposeControl(ctrl As Control)
    If ctrl.HasChildren Then
      For Each c As Control In ctrl.Controls
      DisposeControl(c)
      Next
    End If

    ctrl.Dispose()
End Sub

If this is definitely the source of the leak, are all your resources used by whatever a control calls are being disposed as well? I can't imagine controls being the only factor.