发一个自己封装的PNG透明图片类。

//-----------pnglib.h
#include "stdafx.h"
#include "afxdialogex.h"
#include "atlimage.h"

class DrawImage
{
public:
	DrawImage(UINT, LPCTSTR);
	DrawImage(HWND, UINT, LPCTSTR);
	~DrawImage();
public:
	void Draw(int, int, int, int);
	void Destroy();
	BOOL LoadPNG(UINT, LPCTSTR);
	BOOL LoadPNG(HWND, UINT, LPCTSTR);
	int GetWidth();
	int GetHeight();
private:
	BOOL Load_Resource(CImage *, UINT, LPCTSTR);
	CImage img;
	HDC hDC;
	HWND hWnd;
};

//----------------pnglib.cpp
#include "stdafx.h"
#include "pnglib.h"

DrawImage::DrawImage(UINT nResID, LPCTSTR lpTyp)
{
	LoadPNG(nResID, lpTyp);
}

DrawImage::DrawImage(HWND hWndin, UINT nResID, LPCTSTR lpTyp)
{
	LoadPNG(hWndin, nResID, lpTyp);
}

DrawImage::~DrawImage()
{
	Destroy();
}

int DrawImage::GetWidth()
{
	return img.GetWidth();
}

int DrawImage::GetHeight()
{
	return img.GetHeight();
}

void DrawImage::Draw(int xDest, int yDest, int WidthDest, int HeightDest)
{
	img.Draw(hDC, xDest, yDest, WidthDest, HeightDest);
}

void DrawImage::Destroy()
{
	img.Destroy();
	ReleaseDC(hWnd, hDC);
}

BOOL DrawImage::LoadPNG(UINT nResID, LPCTSTR lpTyp)
{
	hDC = ::GetDC(hWnd);
	return Load_Resource(&img, nResID, lpTyp);
}

BOOL DrawImage::LoadPNG(HWND hWndin, UINT nResID, LPCTSTR lpTyp)
{
	hWnd = hWndin;
	hDC = ::GetDC(hWnd);
	return Load_Resource(&img, nResID, lpTyp);
}

BOOL DrawImage::Load_Resource(CImage *pImage, UINT nResID, LPCTSTR lpTyp)
{
	if (pImage == NULL)
	{
		return false;
	}
	pImage->Destroy();
	HRSRC hRsrc = ::FindResource(AfxGetResourceHandle(), MAKEINTRESOURCE(nResID), lpTyp);
	if (hRsrc == NULL)return false;
	HGLOBAL hImgData = ::LoadResource(AfxGetResourceHandle(), hRsrc);
	if (hImgData == NULL)
	{
		::FreeResource(hImgData);
		return false;
	}
	LPVOID lpVoid = ::LockResource(hImgData);
	LPSTREAM pStream = NULL;
	DWORD dwSize = ::SizeofResource(AfxGetResourceHandle(), hRsrc);
	HGLOBAL hNew = ::GlobalAlloc(GHND, dwSize);
	LPBYTE lpByte = (LPBYTE)::GlobalLock(hNew);
	::memcpy(lpByte, lpVoid, dwSize);
	::GlobalUnlock(hNew);
	HRESULT ht = ::CreateStreamOnHGlobal(hNew, TRUE, &pStream);
	if (ht != S_OK)
	{
		GlobalFree(hNew);
	}
	else
	{
		pImage->Load(pStream);
		GlobalFree(hNew);
	}
	::FreeResource(hImgData);
	for (int i = 0; i < img.GetWidth(); i++)
	{
		for (int j = 0; j < img.GetHeight(); j++)
		{
			unsigned char* puc = reinterpret_cast<unsigned char *>(img.GetPixelAddress(i, j));
			puc[0] = puc[0] * puc[3] / 255;
			puc[1] = puc[1] * puc[3] / 255;
			puc[2] = puc[2] * puc[3] / 255;
		}
	}
	if (img.IsNull())
	{
		return false;
	}
	return true;
}

 用法：

把你的PNG添加到工程里面，修改资源ID为   PIC_PNG1
用法1：默认在当前窗口中绘图
DrawImage m_png(PIC_PNG1,"png");
m_png.Draw(100,100,m_png.GetWidth(),m_png.GetHeight());//其中两个100是图片左上角的坐标

用法2：可以在任何窗口中绘图
HWND hWndin = 桌面句柄；//在桌面绘图，需要自己去获取
DrawImage m_png(hWndin，PIC_PNG1,"png");
m_png.Draw(100,100,m_png.GetWidth(),m_png.GetHeight());

作者：天楼桦