本文所述为一个由CISBitmap派生的VC++位图透明类，可以方便实现BMP图像的透明处理，主要包含两个文件，使用时主需要将其引入到你的C++工程中即可，具体的类代码如下：
CISBitmap.cpp文件代码如下：
#include <stdafx.h>
#include "CISBitmap.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
CCISBitmap::CCISBitmap()
{
m_crBlack = 0;
m_crWhite = RGB(255,255,255);
}
CCISBitmap::~CCISBitmap()
{
}
int CCISBitmap::Width()
{
BITMAP bm;
GetBitmap(&bm);
return bm.bmWidth;
}
int CCISBitmap::Height()
{
BITMAP bm;
GetBitmap(&bm);
return bm.bmHeight;
}
void CCISBitmap::DrawTransparent(CDC * pDC, int x, int y, COLORREF crColour)
{
COLORREF crOldBack = pDC->SetBkColor(m_crWhite);
COLORREF crOldText = pDC->SetTextColor(m_crBlack);
CDC dcImage, dcTrans;
dcImage.CreateCompatibleDC(pDC);
dcTrans.CreateCompatibleDC(pDC);
CBitmap* pOldBitmapImage = dcImage.SelectObject(this);
CBitmap bitmapTrans;
int nWidth = Width();
int nHeight = Height();
bitmapTrans.CreateBitmap(nWidth, nHeight, 1, 1, NULL);
CBitmap* pOldBitmapTrans = dcTrans.SelectObject(&bitmapTrans);
dcImage.SetBkColor(crColour);
dcTrans.BitBlt(0, 0, nWidth, nHeight, &dcImage, 0, 0, SRCCOPY);
pDC->BitBlt(x, y, nWidth, nHeight, &dcImage, 0, 0, SRCINVERT);
pDC->BitBlt(x, y, nWidth, nHeight, &dcTrans, 0, 0, SRCAND);
pDC->BitBlt(x, y, nWidth, nHeight, &dcImage, 0, 0, SRCINVERT);
dcImage.SelectObject(pOldBitmapImage);
dcTrans.SelectObject(pOldBitmapTrans);
pDC->SetBkColor(crOldBack);
pDC->SetTextColor(crOldText);
}
CISBitmap.h文件代码如下：
//请保存为文件名：CISBitmap.h
#if !defined(AFX_CISBITMAP_H__08BA6EB3_DB4C_11D1_8A89_0040052E2D91__INCLUDED_)
#define AFX_CISBITMAP_H__08BA6EB3_DB4C_11D1_8A89_0040052E2D91__INCLUDED_
#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
class CCISBitmap : public CBitmap
{
public:
CCISBitmap();
virtual ~CCISBitmap();
int Height();
int Width();
virtual void DrawTransparent(CDC* pDC, int x, int y, COLORREF crColour);
private:
COLORREF m_crBlack;
COLORREF m_crWhite;
};
#endif // !defined(AFX_CISBITMAP_H__08BA6EB3_DB4C_11D1_8A89_0040052E2D91__INCLUDED_)
感兴趣的朋友可以将本文所述代码放到自己的VC++工程文件中测试一下运行效果，相信会对大家的VC++项目开发起到一定的帮助作用。