TB_GETBUTTON does not populate tooltip button information struct

Hi, I have created a Windows Forms application with a toolbar component which has 3 buttons. I would like to use SendMessage with TB_GETBUTTON message to fetch the first button information. Here is my code:

var tb = new ComCtl32.TBBUTTON();

var buttonCount = User32.SendMessage(mainToolbar.Handle, (uint)ComCtl32.ToolbarMessage.TB_BUTTONCOUNT, (IntPtr)0, 0);
var getButton = User32.SendMessage(mainToolbar.Handle, ComCtl32.ToolbarMessage.TB_GETBUTTON, 0, ref tb);

lblButtonCount.Text = buttonCount.ToString();
lblSuccess.Text = (getButton.ToInt32() != 0).ToString();
lblDWData.Text = tb.dwData.ToString();
lblFSStyle.Text = tb.fsStyle.ToString();
lblFSState.Text = tb.fsState.ToString();
lbliBitmap.Text = tb.iBitmap.ToString();

When I observe tb struct. all properties are zero and have not been populated even though getButton variable is 1 which means success.

The output looks like this:

I created my own class (in naïve implementation) that looks like this:

public sealed class Win32
{
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public extern static int SendMessage(IntPtr hwnd, int msg, int wParam, int lParam);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public extern static unsafe int SendMessage(IntPtr hwnd, int msg, int wParam, void* lParam);
}

And when I use this class in the same form like this:

var tb = new ComCtl32.TBBUTTON();

var buttonCount = Win32.SendMessage(mainToolbar.Handle, (int)ComCtl32.ToolbarMessage.TB_BUTTONCOUNT, 0, 0);

unsafe
{
    var getButton = Win32.SendMessage(mainToolbar.Handle, (int)ComCtl32.ToolbarMessage.TB_GETBUTTON, 0, &tb);
    
    lblButtonCount.Text = buttonCount.ToString();
    lblSuccess.Text = (getButton != 0).ToString();
    lblDWData.Text = tb.dwData.ToString();
    lblFSStyle.Text = tb.fsStyle.ToString();
    lblFSState.Text = tb.fsState.ToString();
    lbliBitmap.Text = tb.iBitmap.ToString();
}

It is populating the struct correctly:

Am I missing anything here? Thanks.

[dahall]

Found the problem. I’ve committed the fix and it will go out in the next week into NuGet and within minutes on AppVeyor.

[dahall]

Thanks. I’ll look at the zip and what’s changed since 3.2.21.