GDI+ 使用

 

第一步: 加载头文件和lib库
#include <gdiplus.h>
#pragma comment(lib, "gdiplus.lib")
using namespace Gdiplus;

第二步:定义全局变量

 Gdiplus::GdiplusStartupInput  gdiplusStartupInput;
ULONG_PTR       gdiplusToken;

第三步:启动

 Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

第四步:关闭

Gdiplus::GdiplusShutdown(gdiplusToken);

第五步: 创建cache二级缓存

   // Create off-screen bitmap
 Gdiplus::Bitmap* m_pMemBitmap =  ::new Bitmap(rcClient.right, rcClient.bottom);

    // Create off-screen graphics
 Gdiplus::Graphics* m_pMemGraphics = ::Graphics::FromImage(m_pMemBitmap);

    // draw to off-screen graphics
 m_pMemGraphics->DrawImage(m_pBkImage, 0, 0,rcClient.right, rcClient.bottom);
 
 // Create cashed bitmap
Gdiplus::CachedBitmap*  m_pCachedBitmap = ::new CachedBitmap(m_pMemBitmap, pGraphics);

//draw

  CPaintDC dc(this); // device context for painting
  Graphics graphics(dc.m_hDC);

graphics.DrawCachedBitmap(m_pCachedBitmap, 0, 0);