Re: .NET TabControl freezes in MFC application

From:

=?Utf-8?B?dmZy?= <vfr@discussions.microsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 26 Aug 2007 13:42:01 -0700

Message-ID:

<0098FDE5-74F3-422F-BDBD-B0B0BF21C465@microsoft.com>

"jorgebnyc@gmail.com" wrote:

On Aug 15, 9:18 am, vfr <v...@discussions.microsoft.com> wrote:

I have an application which integrates new .NET GUI in Usercontrols hosted in
MFC modeless dialogs. When using a .NET TabControl in a Usercontrol the
application freezes when switching between applications on the desktop,
having focus set to one of the controls contained in the tab control. I have
posted another question about this using the MFC04 WinForm integration sample
program, see :
(http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=1840198&SiteID=1)

By using SPY.exe I can see that the TabControl is busy handling
WM_GETDLGCODE, fuDlgCode:DLGC_WANTARROWS|DLGC_WANTCHARS messages continuously.

I found a PRB describing this behaviour for CPropertySheet and CDialog (MFC):
PRB: Child CPropertySheet Hangs If Focus Is Switched. http://support.microsoft.com/kb/149501

It seems like this bug/feature is continued in the new .NET controls. Is
there a workaround or is this bug/feature fixed in a service pack?
How can ModifyStyleEx be used in managed C# code? I cannot find a
WS_EX_CONTROLPARENT style in the resource editor.

I'm using VS2005 (without SP1)

I got around with the same problem (but a different kind of control)
by subscribing to the HandleCreated event of the problematic control
and setting the style of the problem control, as in:

            this.ggc.HandleCreated += new
EventHandler(ggc_HandleCreated);

followed by...

        void ggc_HandleCreated(object sender, EventArgs e)
        {
            if (this.ggc.Handle != IntPtr.Zero)
            {
                HandleRef hr = new HandleRef(this.ggc,
this.ggc.Handle);
                SetWindowLong(
                    hr,
                    GWL_EXSTYLE,
                    GetWindowLong(hr, GWL_EXSTYLE) |
WS_EX_CONTROLPARENT);
            }
        }

        const int GWL_EXSTYLE = -20;
        const int WS_EX_CONTROLPARENT = 0x00010000;

        [DllImport("user32.dll", SetLastError = true)]
        static extern int GetWindowLong(HandleRef hwnd, int idx);
        [DllImport("user32.dll")]
        static extern int SetWindowLong(HandleRef hwnd, int idx, int
newval);

(gcc would be your tabbed control)

Thank you for your response. Your answer will solve the problem. We have
used another method by creating new controls which inherits from the standard
controls , where the new class overrides CreateParams.
The DataGridView Control has exactly the same prioblem.

public class NewTabControl : TabControl
    {
      protected enum WinStyle
      {
        WS_EX_CONTROLPARENT = (int)0x00010000L
      }

      public NewTabControl()
      {

      }

      protected override CreateParams CreateParams
      {
        get
        {
          CreateParams param = base.CreateParams;
          param.ExStyle |= (int)WinStyle.WS_EX_CONTROLPARENT;
          return param;
        }
      }