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 DialogBoxParam

The DialogBoxParam function creates a modal dialog box from a dialog box template resource. 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 DialogBoxParam(
        HINSTANCE   hInstance,
        LPCTSTR     lpTemplateName,
        HWND        hWndParent,
        DLGPROC     lpDialogFunc,
        LPARAM      dwInitParam
    );

Parameters

• hInstance
  [in] Handle to the module whose executable file contains the dialog box template.
• lpTemplateName
  [in] Specifies 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] 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 value of the nResult parameter specified 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 Microsoft Windows. If the function fails for any other reason, the return value is –1. To get extended error information, call GetLastError.

Remarks

The DialogBoxParam function uses the CreateWindowEx function to create the dialog box. DialogBoxParam 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, DialogBoxParam 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.

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: DialogBoxParamW 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