Question

I have an application that currently has a message loop. If I were to create a modal dialog box with the DialogBox method would the current message loop receive messages from the dialog as well or would they be withheld by the runtime?

Answer 1

DialogBox creates its own message loop so your message loop will not run. From the documentation:

The function displays the dialog box (regardless of whether the
template specifies the WS_VISIBLE style), disables the owner window,
and starts its own message loop to retrieve and dispatch messages for
the dialog box.