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 CreateDialogIndirectParam

The CreateDialogIndirectParam function creates a modeless 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

    HWND CreateDialogIndirectParam(  
        HINSTANCE       hInstance,
        LPCDLGTEMPLATE  lpTemplate,
        HWND            hWndParent,
        DLGPROC         lpDialogFunc,
        LPARAM          lParamInit
    );

Parameters

• hInstance
  [in] Handle to the module that will create the dialog box.
• lpTemplate
  [in] Pointer to a global memory object that contains the template CreateDialogIndirectParam 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, 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 dialog box template, the header uses the [DLGTEMPLATEEX] format and the control definitions use the [DLGITEMTEMPLATEEX] format. After CreateDialogIndirectParam returns, you can free the template, which is only used to get the dialog box started.
• 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.
• lParamInit
  [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 window handle to the dialog box.

If the function fails, the return value is NULL. To get extended error information, call GetLastError.

Remarks

The CreateDialogIndirectParam function uses the CreateWindowEx function to create the dialog box. CreateDialogIndirectParam 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 if the template specifies the [WS_VISIBLE] style. Finally, CreateDialogIndirectParam returns the window handle to the dialog box.

After CreateDialogIndirectParam returns, you can use the ShowWindow function to display the dialog box (if it is not already visible). To destroy the dialog box, use the DestroyWindow function. To support keyboard navigation and other dialog box functionality, the message loop for the dialog box must call the IsDialogMessage function.

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 Microsoft Windows 95/98/Me 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: CreateDialogIndirectParamW 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