CStatic with bitmap sensitive to change in system colours

As far as I can see, there is not the same if instead a bitmap is used in the static control. Here is a small class that adds this functionality for bitmaps. This is useful if for instance you add your non-square logo in the About dialog box.

The example figures are from the Database Sample (Repeater Frequency Index) by Eric Hoagland.

To use the class you add a member variable to you dialog header:

protected:
CSysColStatic m_Static;

Then you add the following to OnInitDialog:

BOOL CMyApp::OnInitDialog()
{
	CDialog::OnInitDialog();

	m_Static.SubclassDlgItem(IDC_ARROW_STATIC,this);
	m_Static.ReloadBitmap(IDB_BITMAP1);

The last statement makes the static control reload the bitmap given by IDB_BITMAP1 with correct system colours.

The implementation of the static subclass is very simple:

#if !defined(AFX_SYSCOLSTATIC_H__664DE301_4F7B_11D1_9E3D_00A0245800CF__INCLUDED_)
#define AFX_SYSCOLSTATIC_H__664DE301_4F7B_11D1_9E3D_00A0245800CF__INCLUDED_

#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
// SysColStatic.h : header file
//

/////////////////////////////////////////////////////////////////////////////
// CSysColStatic window

class CSysColStatic : public CStatic
{
// Construction
public:
	CSysColStatic();
	void ReloadBitmap(int nImageID = -1);
// Attributes
public:

// Operations
public:

// Overrides
	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CSysColStatic)
	//}}AFX_VIRTUAL

// Implementation
public:
	virtual ~CSysColStatic();

	// Generated message map functions
protected:
	int m_nImageID;
	//{{AFX_MSG(CSysColStatic)
	afx_msg void OnSysColorChange();
	//}}AFX_MSG

	DECLARE_MESSAGE_MAP()
};

/////////////////////////////////////////////////////////////////////////////

//{{AFX_INSERT_LOCATION}}
// Microsoft Developer Studio will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_SYSCOLSTATIC_H__664DE301_4F7B_11D1_9E3D_00A0245800CF__INCLUDED_)

ReloadBitmap reloads the bitmap identified by m_nImageID. ReloadBitmap is also used to set m_nImageID because I have not found a way to automatically extract the bitmap ID from the control. By loading the bitmap with LoadImage using the LR_LOADMAP3DCOLORS style, the colour changes are done automatically.

A handler is added to respond to WM_SYSCOLORCHANGE messages. It simply calls ReloadBitmap without any arguments.

// SysColStatic.cpp : implementation file
//

#include "stdafx.h"
#include "myapp.h"
#include "SysColStatic.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CSysColStatic

CSysColStatic::CSysColStatic()
{
	m_nImageID == -1;
}

CSysColStatic::~CSysColStatic()
{
}

void CSysColStatic::ReloadBitmap(int nImageID)
{
	if(nImageID != -1)
		m_nImageID = nImageID;

	if(m_nImageID == -1)
		return;

	HBITMAP hBmp = (HBITMAP)::LoadImage( AfxGetInstanceHandle(), 
            MAKEINTRESOURCE(m_nImageID), IMAGE_BITMAP, 0,0, LR_LOADMAP3DCOLORS );

	if( hBmp == NULL )
		return;

	hBmp = SetBitmap(hBmp);
	if(hBmp != NULL)
		::DeleteObject(hBmp);
}

BEGIN_MESSAGE_MAP(CSysColStatic, CStatic)
	//{{AFX_MSG_MAP(CSysColStatic)
	ON_WM_SYSCOLORCHANGE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CSysColStatic message handlers

void CSysColStatic::OnSysColorChange() 
{
	CStatic::OnSysColorChange();
	
	ReloadBitmap();	
}