UltraExpandableGroupBox, Expanded property

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Valentina posted over 15 years ago

Hi everyone!

I have a windows form which has a UltraExpandableGroupBox control. When the form loads, the control shows collapsed, as it was set at design time. That's fine.

Now I would like to expand/collapse the control at runtime, depending on certain variables on the form. So I tried to set the Expanded property on the control in this way:

this.grpDetail.Expanded = true; // (really simple!)

but without any appreciable result.

Curiously, when I debug my application that property is always true, even if the control shows collapsed. Do you have any suggestion? Something I’m missing...?

Thanks, Valentina

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Verified Answer
Matt Snyder posted over 15 years ago in reply to Valentina

Valentina,
This seems to be caused by some of the internal workings of the UltraExpandableGroupBox in terms of its serialization and when it can safely assign the expanded size; I do feel that this is a bug, though, and you should be able to set the value in code immediately after the InitializeComponent call so you should submit this to Developer Support.
As a workaround, using the form's Load event seems to be ok for me, and should still allow you to assign the expanded state of the control based on your condition. If that cannot work for some reason, you could created a control that derives from UltraExpandableGroupBox and override the OnCreateControl method; you would call the base implementation and then set the Expanded state accordingly.
-Matt
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Valentina posted over 15 years ago in reply to Matt Snyder

Hi Matt,
I finally found the problem: it occurs in form's constructor, after calling InitializeComponent method.

If you try adding a breakpoint in .Designer part of form class, where Expanded property is initially set up:

    this.grpDetail.Expanded = false;

you can see that the property's value is always true, both before and after executing that line.

In my application when the form loads the control can be shown expanded or collapsed, depending on some condition. That's the reason why I need to set it inside the constructor, after the execution of InitializeComponent:

    public MainForm() {
      InitializeComponent();
      // some other coding...
      grpDetail.Expanded = true;    /* here it remains collapsed */
    }

Do you think this can be a bug of the component? Anyway, I'll try some workaround...
Bye, Valentina
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Matt Snyder posted over 15 years ago in reply to Valentina

If you do end up being able to reproduce it again, you should submit the sample project to developer support so that it can be looked into and possible be prevented from happening in the future.
-Matt
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Valentina posted over 15 years ago in reply to Matt Snyder

Ok... I created a little test application and it worked (i'm using the latest version of NetAdvantage for .NET, 2008 Vol. 3).
Probably I made some mistake in my app. Now I'll debug more accurately.
Thanks a lot for your quick reply.
Valentina
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Matt Snyder posted over 15 years ago

Valentina,
It's hard to say what's going on here; the Expanded property should certainly not always be showing true if it's collapsed. I just tested this in my application where the group box starts off collapsed and clicking a button expands it, and it worked fine. What is being serialized in the designer code for the ExpandedSize property? I know that there have been bugs in the past regarding the serialization of these properties, so you may want to ensure that you have the latest hotfix.
-Matt
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