CreateDialogIndirectParam

This 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.

At a Glance

Header file:	Winuser.h
Windows CE versions:	1.0 and later

Syntax

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

Parameters

hInstance

[in] Handle to the module that will create the dialog box.

lpTemplate

[in] Long pointer to a global memory object containing a template that 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] Long 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 Values

The window handle to the dialog box indicates success. NULL indicates failure. 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. 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.

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.

Dialog boxes outside the visible area of the screen are not automatically repositioned.

If the user presses ALT+H while the dialog box has the input focus, the system posts a WM_HELP message to the dialog procedure. An application should respond to this message by displaying context-sensitive help for the dialog box.

The following styles are not supported for the style member of the DLGTEMPLATE structure:

DS_SETFONT

You cannot set the font inside dialog boxes.

DS_3DLOOK

Gives the dialog box a non-bold font and draws three-dimensional borders around control windows in the dialog box.

The DS_3DLOOK style is required only by Win32-based applications compiled for system versions earlier than Windows 95 or Windows NT 4.0. The system automatically applies the three-dimensional look to dialog boxes created by applications compiled for current versions of the system.

DS_RECURSE

Not required. Any child dialog box is automatically considered to be a recursive dialog box.

DS_CONTROL

Not required.

To get default positioning, use the DS_CENTER style.

If the WS_CHILD style is not specified, the WS_POPUP style is assumed.