How to Expose Listbox in UserControl in CustomTaskPane VSTO C#


I am creating an application level add-in for Word 2010 using C# VSTO. I created a User Control, placed controls within it, and then used the User Control to add a Custom Task Pane:

UserControl myUserControl; myUserControl = new PageElementsPane(); mytaskPane = this.CustomTaskPanes.Add (myUserControl, "Page Elements", doc.ActiveWindow);

So far so good. However, the User Control contains a listbox that I have not been able to access after the Custom Task Pane is added to the Custom Task Pane collection.

I have tried setting the Modifiers property on the listbox to Public. I have tried exposing the listbox on the User Control as a Public Property:

public partial class PageElementsPane: UserControl { public ListBox ElementsPaneListBox { get { return lbxListbox; } } }

Additionally, I looked at this SO post:

<a href="https://stackoverflow.com/questions/16695909/working-with-listbox-elements-in-a-user-control" rel="nofollow">Working with ListBox elements in a user control</a>

I hoped I could adapt it, but my listbox IntelliSense does not have FindControl, offering FindForm instead. Is there a way to access the listbox within the User Control by somehow interpreting the Custom Task Pane as a form? Any help is greatly appreciated.


It appears my foreach (and hence my cast) was not correct (per Eugene Astafiev's question in the comment above). I found this <a href="https://stackoverflow.com/questions/11223451/casting-new-system-windows-forms-control-object-to-system-windows-forms-textbox" rel="nofollow">SO Post</a> that suggesting looping with type Control instead of UserControl. I did this and all was good. Here is the code:

foreach (Control lbxControl in myUserControl.Controls) { if (lbxControl is ListBox) { ((ListBox)lbxControl).SelectedIndex = 1; } }


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