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 DialogBoxIndirectParam

The DialogBoxIndirectParam function creates a modal dialog box from a dialog box template in memory. Before displaying the dialog box, the function passes an application-defined value to the dialog box procedure as the lParam parameter of the WM_INITDIALOG message. An application can use this value to initialize dialog box controls.

Syntax

    INT_PTR DialogBoxIndirectParam(      
        HINSTANCE       hInstance,
        LPCDLGTEMPLATE  hDialogTemplate,
        HWND            hWndParent,
        DLGPROC         lpDialogFunc,
        LPARAM          dwInitParam
    );

Parameters

• hInstance
  [in] Handle to the module that creates the dialog box.
• hDialogTemplate
  [in] Pointer to a global memory object that contains the template that DialogBoxIndirectParam 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.
• hWndParent
  [in] Handle to the window that owns the dialog box.
• lpDialogFunc
  [in] Pointer to the dialog box procedure. For more information about the dialog box procedure, see DialogProc.
• dwInitParam
  [in] Specifies the value to pass to the dialog box in the lParam parameter of the WM_INITDIALOG message.

Return Value

If the function succeeds, the return value is the nResult parameter specified in the call to the EndDialog function that was 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 Microsoft Windows. If the function fails for any other reason, the return value is –1. To get extended error information, call GetLastError.

Remarks

The DialogBoxIndirectParam function uses the CreateWindowEx function to create the dialog box. DialogBoxIndirectParam 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, DialogBoxIndirectParam 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. To create code that works on both Windows 95/98 and Windows NT/2000/XP, use the [MultiByteToWideChar] function to generate these Unicode strings.

Windows 95/98/Me:The system can support a maximum of 255 controls per dialog box template. To place more than 255 controls in a dialog box, create the controls in the WM_INITDIALOG message handler rather than placing them in the template.

Windows 95/98/Me: DialogBoxIndirectParamW is supported by the Microsoft Layer for Unicode. To use this, you must add certain files to your application, as outlined in Microsoft Layer for Unicode on Windows 95/98/Me Systems .

Function Information

• Minimum DLL Version user32.dll
• Header Declared in Winuser.h, include Windows.h
• Import library User32.lib
• Minimum operating systems Windows 95, Windows NT 3.1
• Unicode Implemented as ANSI and Unicode versions.

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time