Notification Functions (GDI+)

Return Values

If the function succeeds, it returns Ok, which is an element of the Status enumeration.

 

If the function fails, it returns one of the other elements of the Status enumeration.

GdiplusNotificationHook

Description

The GdiplusStartup function returns (in its output parameter) a pointer to a GdiplusStartupOutput structure. One of the members of the structure is a pointer to a notification hook function that has the same signature as GdiplusNotificationHook.

 

There are two ways you can call the notification hook function; you can use the pointer returned by GdiplusStartup or you can call GdiplusNotificationHook. In fact, GdiplusNotificationHook simply verifies that you have suppressed the background thread and then calls the notification hook function that is returned by GdiplusStartup.

 

The token parameter receives an identifier that you should later pass in a corresponding call to the notification unhook function.

Syntax

GpStatus WINGDIPAPI GdiplusNotificationHook(

    OUT ULONG_PTR *token

);

PowerBASIC Syntax

DECLARE FUNCTION GdiplusNotificationHook ( _

    BYREF token AS DWORD _

) AS LONG

Parameters

token

[out] Pointer to a variable that receives an identifier that you should later pass in a corresponding call to the notification unhook function.

Return Value

If the function succeeds, it returns Ok, which is an element of the Status enumeration.

 

If the function fails, it returns one of the other elements of the Status enumeration.

GdiplusNotificationUnhook

Description

The GdiplusStartup function returns (in its output parameter) a pointer to a GdiplusStartupOutput structure. One of the members of the structure is a pointer to a notification unhook function that has the same signature as GdiplusNotificationUnhook.

 

There are two ways you can call the notification unhook function; you can use the pointer returned by GdiplusStartup or you can call GdiplusNotificationUnhook. In fact, GdiplusNotificationUnhook simply verifies that you have suppressed the background thread and then calls the notification unhook function that is returned by GdiplusStartup.

 

When you call the notification unhook function, pass the token that you previously received from a corresponding call to the notification hook function. If you do not do this, there will be resource leaks that won't be cleaned up until the process exits.

Syntax

GpStatus WINGDIPAPI GdiplusNotificationUnhook(

    OUT ULONG_PTR token

);

PowerBASIC Syntax

DECLARE FUNCTION GdiplusNotificationUnhook ( _

    BYVAL token AS DWORD _

) AS LONG

Parameters

token

[in] Identifier previously received from a corresponding call to the GdipNotificationHook function.

Return Value

If the function succeeds, it returns Ok, which is an element of the Status enumeration.

 

If the function fails, it returns one of the other elements of the Status enumeration.