[MFC]no subclass, no derivation, just redirect one function of CButton, is it possible?

Falconapollo

As shown below, there are a few functions in CButton, but i want to change its behaviour by dealing with

virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)

. Yes, just this one and only one functon. It would generate more code than expected if I derive a class from CButton. I wonder if it possible to process this function without Subclass, and not use derivation. If so, how? Remarks: I must use MFC, it's so hard to use pure Win32 API.

class CButton : public CWnd
{
DECLARE_DYNAMIC(CButton)

// Constructors
public:
CButton();
virtual BOOL Create(LPCTSTR lpszCaption, DWORD dwStyle,
const RECT& rect, CWnd* pParentWnd, UINT nID);

// Attributes
UINT GetState() const;
void SetState(BOOL bHighlight);
int GetCheck() const;
void SetCheck(int nCheck);
UINT GetButtonStyle() const;
void SetButtonStyle(UINT nStyle, BOOL bRedraw = TRUE);

HICON SetIcon(HICON hIcon);
HICON GetIcon() const;
HBITMAP SetBitmap(HBITMAP hBitmap);
HBITMAP GetBitmap() const;
HCURSOR SetCursor(HCURSOR hCursor);
HCURSOR GetCursor();

#if (_WIN32_WINNT >= 0x501)
AFX_ANSI_DEPRECATED BOOL GetIdealSize(_Out_ LPSIZE psize) const;
AFX_ANSI_DEPRECATED BOOL SetImageList(_In_ PBUTTON_IMAGELIST pbuttonImagelist);
AFX_ANSI_DEPRECATED BOOL GetImageList(_In_ PBUTTON_IMAGELIST pbuttonImagelist) const;
AFX_ANSI_DEPRECATED BOOL SetTextMargin(_In_ LPRECT pmargin);
AFX_ANSI_DEPRECATED BOOL GetTextMargin(_Out_ LPRECT pmargin) const;
#endif // (_WIN32_WINNT >= 0x501)

#if ( _WIN32_WINNT >= 0x0600 ) && defined(UNICODE)
CString GetNote() const;
_Check_return_ BOOL GetNote(_Out_z_cap_(*pcchNote) LPTSTR lpszNote, _Inout_ UINT* pcchNote) const;
BOOL SetNote(_In_z_ LPCTSTR lpszNote);
UINT GetNoteLength() const;
BOOL GetSplitInfo(_Out_ PBUTTON_SPLITINFO pInfo) const;
BOOL SetSplitInfo(_In_ PBUTTON_SPLITINFO pInfo);
UINT GetSplitStyle() const;
BOOL SetSplitStyle(_In_ UINT nStyle);
BOOL GetSplitSize(_Out_ LPSIZE pSize) const;
BOOL SetSplitSize(_In_ LPSIZE pSize);
CImageList* GetSplitImageList() const;
BOOL SetSplitImageList(_In_ CImageList* pSplitImageList);
TCHAR GetSplitGlyph() const;
BOOL SetSplitGlyph(_In_ TCHAR chGlyph);
BOOL SetDropDownState(_In_ BOOL fDropDown);

// Sets whether the action associated with the button requires elevated permissions.
// If elevated permissions are required then the button should display

Lost User

I'm not sure I understand exactly what you want to do, but I do not think there is any way to override a single method unless you derive your own class from CButton. The documentation at http://msdn.microsoft.com/en-us/library/y0k9f0a4.aspx[^] shows an example.

Falconapollo

then, how about Hook?

CPallini

Inheritance is the natural way for doing that. Any other way (if feasible) would be contrived.

Veni, vidi, vici.

Lost User

Falconapollo wrote:

how about Hook?

What does that have to do with drawing a CButton? Hooks are system wide so you would need to capture every drawing message and then decide whether it was for your control or not. That's like using a big hammer to crack a small nut.

_Superman_

WTL is a light weight template library for creating UI controls. Michael Dunn[^] has written some great articles about WTL. These couple of articles would be useful for you - WTL for MFC Programmers, Part IV - Dialogs and Controls[^] WTL for MFC Programmers, Part V - Advanced Dialog UI Classes[^]

«_Superman_» _I love work. It gives me something to do between weekends.

_Microsoft MVP (Visual C++) (October 2009 - September 2013)

Polymorphism in C