This 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.
int DialogBoxIndirectParam( HINSTANCE hInstance, LPCDLGTEMPLATE hDialogTemplate, HWND hWndParent, DLGPROC lpDialogFunc, LPARAM dwInitParam );
[in] Handle to the module that creates the dialog box.
[in] Handle to a global memory object containing a 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] Handle to the window that owns the dialog box.
[in] Long pointer to the dialog box procedure. For more information about the dialog box procedure, see DialogProc.
[in] Specifies the value to pass to the dialog box in the lParam parameter of the WM_INITDIALOG message.
The DialogBoxIndirectParam function uses the CreateWindowEx function to create the dialog box. DialogBoxIndirectParam then sends a WM_INITDIALOG 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 value of 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.
All character strings in the dialog box template, such as titles for the dialog box and buttons, must be Unicode strings.
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.
For other dialog restrictions, see CreateDialogIndirectParam.