LPFNPSPCALLBACKA callback function (prsht.h)

Article
11/20/2024

Specifies an application-defined callback function that a property sheet calls when a page is created and when it is about to be destroyed. An application can use this function to perform initialization and cleanup operations for the page.

Syntax

LPFNPSPCALLBACKA Lpfnpspcallbacka;

UINT Lpfnpspcallbacka(
            HWND hwnd,
  [in]      UINT uMsg,
  [in, out] _PROPSHEETPAGEA *ppsp
)
{...}

Parameters

hwnd

Type: HWND

Reserved; must be NULL.

[in] uMsg

Type: UINT

Action flag. This parameter can be one of the following values.

Value	Meaning
PSPCB_ADDREF	Version 5.80 or later. A page is being created. The return value is not used.
PSPCB_CREATE	A dialog box for a page is being created. Return nonzero to allow it to be created, or zero to prevent it.
PSPCB_RELEASE	A page is being destroyed. The return value is ignored.

[in, out] ppsp

Type: LPPROPSHEETPAGE

Pointer to a PROPSHEETPAGE structure that defines the page being created or destroyed. See the Remarks section for further discussion.

Return value

Type: UINT

The return value depends on the value of the uMsg parameter.

Remarks

An application must specify the address of this callback function in the pfnCallback member of a PROPSHEETPAGE structure before passing the structure to the CreatePropertySheetPage function.

Note The property sheet is in the process of manipulating the list of pages when this function is called. Do not attempt to add, remove, or insert pages while handling this notification. Doing so will have unpredictable results.

With the exception of the lParam member, your application should not modify the PROPSHEETPAGE structure. Doing so will have unpredictable results. The lParam member contains application-defined data and can be modified as needed.

Note

The prsht.h header defines LPFNPSPCALLBACK as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	prsht.h

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