使用Windows API将无模式对话框嵌入为子窗口

Question

I know, there must be a way to embed an (modeless) dialog as child of a window created with CreateWindow . In my case I want to embed them into an scroll-able container window, whereby this container windows it self is a child of the main window (see picture).

The first problem that I encounter is, that I still want be able to use TAB keys and other dialog specific navigation. But how?

My message loop:

while (GetMessage(&msg, NULL, 0, 0)) {
    if (IsDialogMessage(msg.hwnd, &msg)) continue;
    if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

Edit: For testing purpose I modified the loop:

while (GetMessage(&msg, NULL, 0, 0)) {
    if (IsEmbeddedDialogWindow(msg.hwnd)) {
        if (IsDialogMessage(msg.hwnd, &msg)) continue;
    }
    if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

while (GetMessage(&msg, NULL, 0, 0)) {
    if (IsScrollableContainerWindow(msg.hwnd)) {
        if (IsDialogMessage(msg.hwnd, &msg)) continue;
    }
    if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

More information how to make it the right way can be found here: Using the TAB key to navigate in non-dialogs, redux

With this message loop, nothing happens if I want to enter some dialog texts as if the message is not handled. If IsDialogMessage is removed, I can enter some text into an edit control in one of the embedded dialogs, however dialog navigation doesn't work as intended. Of course, WS_TABSTOP style is set for dialog child controls.

The scroll-able container is created with CreateWindowEx with styles WS_CHILD, WS_VISIBLE, WS_VSCROLL, WS_TABSTOP, WS_EX_CONTROLPARENT and dialogs are created as children of this container.

    HWND hWndContainer = GroupBarPanelCreate(WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_TABSTOP, WS_EX_CONTROLPARENT, hWndMain, 0, 0, 400, 400);
    GROUPBAR_PANEL* GroupBarPanel = (GROUPBAR_PANEL*) GetWindowLongPtr(hWndContainer, 0);
    // Test embedding dialogs
    for (unsigned int i = 0; i < 10; i++) {
        HWND hWndDlg = CreateDialogParam(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWndContainer, About, 0);
        GroupBarPanelInternalAddLast(GroupBarPanel, hWndChild, hWndDlg, nullptr);
    }

My GroupBarPanelInternalAddLast modify modeless dialog styles by removing caption and borders, and ensures that WS_CHILD , WS_VISIBLE and WS_TABSTOP is set ( SetWindowLong(hWndDlg, GWL_STYLE, ...) ). (Also tested WS_EX_CONTROLPARENT style) With SetParent(hWndDlg, hWndContainer) modeless dialogs parent is changed.

So what am I missing here? As I found out, neither the container window procedure nor the embedded (for testing purpose subclassed) dialog procedure almost never gets WM_SETFOCUS or WM_KILLFOCUS messages for example, but why that?

Solution: Calling IsDialogMessage for the top level window.

while (GetMessage(&msg, NULL, 0, 0)) {
    if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) {
        if (IsDialogMessage(hWndTopLevel, &msg)) {
            continue;
        }
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

Answer 1

You are not using IsDialogMessage() correctly, and you said you learned from some bad tutorials. I don't know which tutorials you saw, so I can't tell you what they got wrong; all I can do is say how to use it correctly.

IsDialogMessage() takes two parameters: the message itself, and the window handle of the toplevel window . This bit in bold is the important part: the IsDialogMessage() function needs to know which dialog to work with in the event of tab navigation or Enter/Esc handling.

You don't want to pass msg.hwnd ; that's the control itself.

And in the case of nested child dialogs like you have here, you don't want to pass in the child dialog's handle; that would confine IsDialogMessage() to that dialog.

So in your screenshot, you want to pass in the handle of the main window, that is, the window called Win32ApiDemo1 .

Also make sure all the child dialogs and your custom expander control have WS_EX_CONTROLPARENT so tab navigation can recurse.