PFNWP: Difference between revisions

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Revision as of 16:46, 27 May 2005

PFNWP

Pointer to a window procedure.

Type

FNWP

C Declaration Method

typedef

Coment

In the header file, this is a two-part definition as shown below:

typedef MRESULT (EXPENTRY FNWP) (HWND, ULONG, MPARAM, MPARAM); 
typedef FNWP *PFNWP;

The first argument (HWND) is the handle of the window receiving the message. The second argument (ULONG) is a message identifier. The third argument (MPARAM) is the first message parameter (mp1). The fourth argument (MPARAM) is the second message parameter (mp2). The function returns an MRESULT.

This is the standard function definition for window procedures. Each message has a specific set of possible return codes. The window procedure must return a value that is appropriate for the message being processed.

Window procedures must be exported in the definitions file used by the linker.

@@ Line 1: / Line 1: @@
-== Type ==
+== PFNWP ==
-[[OS2 API:DataType:MRESULT|MRESULT]] ([[OS2 API:DataType:EXPENTRY|EXPENTRY]] FNWP) ([[OS2 API:DataType:HWND|HWND]], [[OS2 API:DataType:ULONG|ULONG]], [[OS2 API:DataType:MPARAM|MPARAM]], [[OS2 API:DataType:MPARAM|MPARAM]])
-== Value ==
+Pointer to a window procedure.
+=== Type ===
 FNWP
+==== C Declaration Method ====
+typedef
+=== Coment ===
+In the header file, this is a two-part definition as shown below:
+ typedef [[OS2 API:DataType:MRESULT|MRESULT]] ([[OS2  API:DataType:EXPENTRY|EXPENTRY]] FNWP) ([[OS2 API:DataType:HWND|HWND]], [[OS2  API:DataType:ULONG|ULONG]], [[OS2 API:DataType:MPARAM|MPARAM]], [[OS2  API:DataType:MPARAM|MPARAM]]);
+ typedef FNWP *PFNWP;
+The first argument ([[OS2 API:DataType:HWND|HWND]]) is the handle of the window receiving the message.
+The second argument ([[OS2 API:DataType:ULONG|ULONG]]) is a message identifier.
+The third argument ([[OS2 API:DataType:MPARAM|MPARAM]]) is the first message parameter (mp1).
+The fourth argument ([[OS2 API:DataType:MPARAM|MPARAM]]) is the second message parameter (mp2).
+The function returns an [[OS2 API:DataType:MRESULT|MRESULT]].
+This is the standard function definition for window procedures.
+Each message has a specific set of possible return codes. The window procedure must return a value that is appropriate for the message being processed.
+'''Window procedures must be exported''' in the definitions file used by the linker.