MDI Child handles not working (.NET)

[Unregistered]

I am currently working on an application that utilizes the .NET Framework's windows forms, and it's written in C#. I can add a TextControl, ruler, and buttons to my form, and it all works correctly; however, when I set the MdiParent property of my form, then I lose the handles to my button and ruler controls.

If I step through the code, I see the values for the RulerControl.hWnd and the ButtonControl.hWnd, but as soon as I set the MdiParent then they both go to 0. Then, I'm unable to use the controls correctly.

I'm getting this error if I set the MdiChild property before or after I set the axControl.ButtonHandle or .RulerHandle.

Is there anything that I can do to work around this? My code is attached below.

Thanks,

Sean

public frmTemplateManager(UIController uiController, EnumMode enumMode)
{
InitializeComponent();

myController = uiController;
this.MdiParent = myController.MdiParent;

axRTFControl.ButtonBarHandle = axRTFButtons.hWnd;
axRTFControl.RulerHandle = axRTFRuler.hWnd;

axRTFControl.ScrollBars = (short)ScrollBars.Both; // both

formMode = (int)enumMode;
}


This message was originally posted by Sean Baughman in the old TX Text Control Support Forum.

[Unregistered]

I'm wondering if Handle would reveal it:

axRTFControl.ButtonBarHandle = axRTFButtons.Handle.ToInt32;
axRTFControl.RulerHandle = axRTFRuler.Handle.ToInt32;


This message was originally posted by Vann Joe in the old TX Text Control Support Forum.

[Unregistered]

I tried the above code (using handles) and it doesn't work either. I have valid handle numbers, and my code doesn't throw any exceptions -- it just doesn't enable the ruler or button controls.

It's as if once I set that property then I can no longer access those handles. Then I have no access to my ruler or buttons anymore.

Any ideas?


This message was originally posted by Sean Baughman in the old TX Text Control Support Forum.

[Unregistered]

I think the problem you're having is passing an unmanaged control (the TX ActiveX controls) between classes (ie forms). When you do so, you can only pass them as a generic Control, and you have to use boxing/unboxing to reconstitute the control in usable form. From a design standpoint, this makes sense, for there is no way in advance for the CLR to know about the structure of an ActiveX object.

I spent 5 minutes creating a hasty project with TX that properly links the button bar to the control itself. I know the code snippet below isn't pretty or elegant, but I think it'll get you on the right track:
Private Sub NewDoc(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MenuNewFile.Select
Dim f As New Form2()
f.MdiParent = Me
f.Show()
Dim TX As AxTx4oleLib.AxTXTextControl
Dim ButBar As AxTx4oleLib.AxTXButtonBar
ButBar = CType(Me.AxTXButtonBar1, AxTx4oleLib.AxTXButtonBar)
TX = CType(f.Controls(0), AxTx4oleLib.AxTXTextControl)
TX.ButtonBarHandle = ButBar.Handle.ToInt32
End Sub

This message was originally posted by Vann Joe in the old TX Text Control Support Forum.