DialogBox function

Creates a modal dialog box from a dialog box template resource. DialogBox does not return control until the specified callback function terminates the modal dialog box by calling the EndDialog function.

DialogBox is implemented as a call to the DialogBoxParam function.

Syntax

INT_PTR WINAPI DialogBox(
  _In_opt_ HINSTANCE hInstance,
  _In_     LPCTSTR   lpTemplate,
  _In_opt_ HWND      hWndParent,
  _In_opt_ DLGPROC   lpDialogFunc
);

Parameters

hInstance [in, optional]

Type: HINSTANCE

A handle to the module which contains the dialog box template. If this parameter is NULL, then the current executable is used.

lpTemplate [in]

Type: LPCTSTR

The dialog box template. This parameter is either the pointer to a null-terminated character string that specifies the name of the dialog box template or an integer value that specifies the resource identifier of the dialog box template. If the parameter specifies a resource identifier, its high-order word must be zero and its low-order word must contain the identifier. You can use the MAKEINTRESOURCE macro to create this value.

hWndParent [in, optional]

Type: HWND

A handle to the window that owns the dialog box.

lpDialogFunc [in, optional]

Type: DLGPROC

A pointer to the dialog box procedure. For more information about the dialog box procedure, see DialogProc.

Return value

Type: INT_PTR

If the function succeeds, the return value is the nResult parameter in the call to the EndDialog function used to terminate the dialog box.

If the function fails because the hWndParent parameter is invalid, the return value is zero. The function returns zero in this case for compatibility with previous versions of Windows. If the function fails for any other reason, the return value is –1. To get extended error information, call GetLastError.

This function typically fails for one of the following reasons:

• an invalid parameter value
• the system class was registered by a different module
• The WH_CBT hook is installed and returns a failure code
• if one of the controls in the dialog template is not registered, or its window window procedure fails WM_CREATE or WM_NCCREATE

Remarks

The DialogBox macro uses the CreateWindowEx function to create the dialog box. DialogBox then sends a WM_INITDIALOG message (and a WM_SETFONT message if the template specifies the DS_SETFONT or DS_SHELLFONT style) to the dialog box procedure. 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.

When the dialog box procedure calls the EndDialog function, DialogBox destroys the dialog box, ends the message loop, enables the owner window (if previously enabled), and returns the nResult parameter specified by the dialog box procedure when it called EndDialog.

Examples

For an example, see Creating a Modal Dialog Box.

Requirements

See also

Reference

CreateDialog

CreateWindowEx

DialogBoxIndirect

DialogBoxIndirectParam

DialogBoxParam

DialogProc

EndDialog

MAKEINTRESOURCE

WM_INITDIALOG

WM_SETFONT

Conceptual

Dialog Boxes