Question

I’ve created my dialog as a resource using the resource editor (dialog editor?)

It’s nothing special, just two groupboxes, two buttons, a split button, two pictureboxes, 3 static labels, 3 edit boxes, 3 spin controls, 3 syslinks, and a progressbar.

When I press Ctrl+T to test the dialog, it appears to work fine, but when I press F5 to debug the program, the dialog never appears and the program exits with code -1 (0xffffffff)

Here is the code I’m using to call the dialog:

#include <Windows.h>
#include "resource.h"

BOOL CALLBACK DlgProc(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
    switch (Msg)
    {
        case (WM_COMMAND):
            switch (LOWORD(wParam))
            {
                default:
                    break;
            }
            break;

        default:
            return FALSE;
    }

    return FALSE;
}

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    int ret = DialogBox(hInstance, MAKEINTRESOURCE(IDD_MAINWINDOW), NULL, DlgProc);

    int err = GetLastErro(); // This gives 0

    return ret; // This gives -1
}

I don’t have anything yet in the DlgProc yet because I just wanted the dialog to show to begin with.

If I set a breakpoint in DlgProc then these are the messages it receives:

48, 85, 297, 273, 273, 144, 2, and 130.

I’ve looked these up and they translate to:

WM_SETFONT
WM_NOTIFYFORMAT
???
WM_COMMAND
WM_COMMAND
???
WM_DESTROY
WM_NCDESTROY

Anybody know what I’m doing wrong?

---

Edit::
I found a solution to the problem! We originally thought it was a corrupted RC file but I realised the the test RC file I made has every type of control except a SysLink. When I added a SysLink the same thing happened. I tried including ComCtl32.lib in the linker, and I also tried including the common controls header and calling InitCommonControls but that did nothing.

I put everything back the way it originally was, and added this pre-processor directive which fixed it:

#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")

That was the problem. Without that directive, the dialog won’t initialise because of the SysLinks!

Answer 1

You don’t need to call DefWindowProc for Dialog procs. They are done for you by the OS. simply return FALSE;