Marsc
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Registering a window class.
Hello Experts.
To register a window class... whe have this structure:
typedef struct _WNDCLASSEX {
UINT cbSize;
UINT style;
WNDPROC lpfnWndProc;
int cbClsExtra;
int cbWndExtra;
HANDLE hInstance;
HICON hIcon;
HCURSOR hCursor;
HBRUSH hbrBackground;
LPCTSTR lpszMenuName;
LPCTSTR lpszClassName;
HICON hIconSm;
} WNDCLASSEX;
Theese members:
int cbClsExtra;
int cbWndExtra;
In the MSDN:
cbClsExtra
Specifies the number of extra bytes to allocate following the window-class structure. The system initializes the bytes to zero.
cbWndExtra
Specifies the number of extra bytes to allocate following the window instance. The system initializes the bytes to zero. If an application uses WNDCLASSEX to register a dialog box created by using the CLASS directive in the resource file, it must set this member to DLGWINDOWEXTRA
Well finally my question... Why would I want to allocate extra bytes... How can I use them?.
Thanks.
To register a window class... whe have this structure:
typedef struct _WNDCLASSEX {
UINT cbSize;
UINT style;
WNDPROC lpfnWndProc;
int cbClsExtra;
int cbWndExtra;
HANDLE hInstance;
HICON hIcon;
HCURSOR hCursor;
HBRUSH hbrBackground;
LPCTSTR lpszMenuName;
LPCTSTR lpszClassName;
HICON hIconSm;
} WNDCLASSEX;
Theese members:
int cbClsExtra;
int cbWndExtra;
In the MSDN:
cbClsExtra
Specifies the number of extra bytes to allocate following the window-class structure. The system initializes the bytes to zero.
cbWndExtra
Specifies the number of extra bytes to allocate following the window instance. The system initializes the bytes to zero. If an application uses WNDCLASSEX to register a dialog box created by using the CLASS directive in the resource file, it must set this member to DLGWINDOWEXTRA
Well finally my question... Why would I want to allocate extra bytes... How can I use them?.
Thanks.
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