DialogBoxIndirectA macro (winuser.h)

Article
02/09/2023

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

DialogBoxIndirect is implemented as a call to the DialogBoxIndirectParam function.

Syntax

void DialogBoxIndirectA(
  [in, optional]  hInstance,
  [in]            lpTemplate,
  [in, optional]  hWndParent,
  [in, optional]  lpDialogFunc
);

Parameters

[in, optional] hInstance

Type: HINSTANCE

A handle to the module that creates the dialog box.

[in] lpTemplate

Type: LPCDLGTEMPLATE

The template that DialogBoxIndirect uses to create the dialog box. A dialog box template consists of a header that describes the dialog box, followed by one or more additional blocks of data that describe each of the controls in the dialog box. The template can use either the standard format or the extended format.

In a standard template for a dialog box, the header is a DLGTEMPLATE structure followed by additional variable-length arrays. The data for each control consists of a DLGITEMTEMPLATE structure followed by additional variable-length arrays.

In an extended template for a dialog box, the header uses the DLGTEMPLATEEX format and the control definitions use the DLGITEMTEMPLATEEX format.

[in, optional] hWndParent

Type: HWND

A handle to the window that owns the dialog box.

[in, optional] lpDialogFunc

Type: DLGPROC

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

Return value

None

Remarks

The DialogBoxIndirect macro uses the CreateWindowEx function to create the dialog box. DialogBoxIndirect then sends a WM_INITDIALOG message to the dialog box procedure. If the template specifies the DS_SETFONT or DS_SHELLFONT style, the function also sends a WM_SETFONT message 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, DialogBoxIndirect 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.

In a standard dialog box template, the DLGTEMPLATE structure and each of the DLGITEMTEMPLATE structures must be aligned on DWORD boundaries. The creation data array that follows a DLGITEMTEMPLATE structure must also be aligned on a DWORD boundary. All of the other variable-length arrays in the template must be aligned on WORD boundaries.

In an extended dialog box template, the DLGTEMPLATEEX header and each of the DLGITEMTEMPLATEEX control definitions must be aligned on DWORD boundaries. The creation data array, if any, that follows a DLGITEMTEMPLATEEX structure must also be aligned on a DWORD boundary. All of the other variable-length arrays in the template must be aligned on WORD boundaries.

All character strings in the dialog box template, such as titles for the dialog box and buttons, must be Unicode strings. Use the MultiByteToWideChar function to generate Unicode strings from ANSI strings.

Examples

For an example, see Creating a Template in Memory.

Note

The winuser.h header defines DialogBoxIndirect as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll

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