常用的GDI+ 函数使用例子

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一、通过Gdi+加载和显示PNG，JPG等格式的图片

//直接加载外部的图像

Image* image = new Image(L"test.png");//如果需要通过ID 来加载的话

BOOL CSmalltmpdemoDlg::ImageFromIDResource(UINT nID, LPCTSTR sTR, Image * & pImg){    HINSTANCE hInst = AfxGetResourceHandle();    HRSRC hRsrc = ::FindResource (hInst,MAKEINTRESOURCE(nID),sTR); // type    if (!hRsrc)        return FALSE;    // load resource into memory    DWORD len = SizeofResource(hInst, hRsrc);    BYTE* lpRsrc = (BYTE*)LoadResource(hInst, hRsrc);    if (!lpRsrc)        return FALSE;    // Allocate global memory on which to create stream    HGLOBAL m_hMem = GlobalAlloc(GMEM_FIXED, len);    BYTE* pmem = (BYTE*)GlobalLock(m_hMem);    memcpy(pmem,lpRsrc,len);    IStream* pstm;    CreateStreamOnHGlobal(m_hMem,FALSE,&pstm);    // load from stream    pImg=Gdiplus::Image::FromStream(pstm);    // free/release stuff    GlobalUnlock(m_hMem);    pstm->Release();    FreeResource(lpRsrc);    return TRUE;}

//调用方式

Image * pImage = NULL; ImageFromIDResource(IDR_PNG_NO_PIC, L"png", pImage); delete pImage; /////////////////////////////////////////////////////////////////////////  Image * pImage = NULL; ImageFromIDResource(IDR_PNG_NO_PIC, L"jpg", pImage); delete pImage; //////////////////////////////////////////////////////////////////////////  Image * pImage = NULL; ImageFromIDResource(IDR_PNG_NO_PIC, L"bitmap", pImage); delete pImage;

二、实现一个渐变的画刷

  CClientDC dc(this);  CRect rect;  //获得当前客户区的大小  GetClientRect(&rect);  //创建Graphics对象  Graphics graphics(dc);  //创建渐变画刷  LinearGradientBrush lgb(Point(0, 0), Point(rect.right, rect.bottom), Color    ::Blue, Color::Green);  //填充  graphics.FillRectangle(&lgb, 0, 0, rect.right, rect.bottom);