To use a modeless dialog window in an application, create a dialog template in the resource file, just as for a modal dialog window. Modeless dialog windows share the screen equally with other frame windows. It is a good idea to give modeless dialog windows a title bar so they can be moved around the screen. The following Resource Compiler source-code fragment shows a dialog template for a dialog window with a title bar, system menu, and minimize button.

    DLGTEMPLATE IDD_SAMP
    BEGIN
        DIALOG "Modeless Dialog", IDD_SAMP, 80, 92, 126, 130,
            WS_VISIBLE | FS_DLGBORDER,
            FCF_TITLEBAR | FCF_SYSMENU | FCF_MINBUTTON

        BEGIN

        /* Put control-window definitions here. */

        END
    END

The application loads the dialog resource from the resource file using the WinLoadDlg function, receiving in return a window handle to the dialog window. The application treats the dialog window as if it were an ordinary window. Messages for the dialog window are dispatched through the event loop the application uses for its other windows. In fact, an application can have a modeless dialog window as its only window.

The resource for a modeless dialog window is like the resource used for a modal dialog window. The difference between modal and modeless dialog windows is the way applications handle input to each. For a modal dialog, the WinDlgBox and WinProcessDlg functions handle all user input to the dialog window, preventing access to other windows in the application. For a modeless dialog window, the application does not call these functions, relying instead on a normal message loop to dispatch messages to the dialog procedure.

The primary difference between a modeless dialog window and a standard frame window with child control windows is that, for a modeless dialog window, an application can define child windows for the dialog window in a dialog template, automating the process of creating the window and its child windows. The same effect can be achieved by creating a standard frame window, but then, the child control windows must be created individually.

It is important that an application keep track of all open modeless dialog windows so that it can destroy all open windows before terminating.