asp.net中C實現縮放圖片的例子

標頭檔:

代碼如下	複製代碼
#include <atlconv.h> #include <AtlBase.h> #include <tchar.h> #include "gdiplus.h" #include <GdiPlusGraphics.h> using namespace Gdiplus; #pragma comment(lib, "gdiplus.lib")

CPP:

代碼如下

複製代碼

int GetEncoderClsid(const WCHAR* format, CLSID* pClsid) { UINT  num = 0;  // number of image encoders UINT  size = 0; // size of the image encoder array in bytes   ImageCodecInfo* pImageCodecInfo = NULL;   GetImageEncodersSize(&num, &size); if(size == 0) return -1;  // Failure www.111cn.net   pImageCodecInfo = (ImageCodecInfo*)(malloc(size)); if(pImageCodecInfo == NULL) return -1;  // Failure   GetImageEncoders(num, size, pImageCodecInfo);   for(UINT j = 0; j < num; ++j) { if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 ) { *pClsid = pImageCodecInfo[j].Clsid; free(pImageCodecInfo); return j;  // Success } }   free(pImageCodecInfo); return -1;  // Failure }   void DrawMainWindow(Image* img,int w,int h) { HDC hDC = GetDC(AfxGetMainWnd()->m_hWnd); if (hDC) { Graphics graphics(hDC); graphics.DrawImage(img,w,h,img->GetWidth(),img->GetHeight()); ReleaseDC(AfxGetMainWnd()->m_hWnd,hDC); }   }   void GetThumbnail(LPCSTR srcFile,LPCSTR dstFile,int width,int height,bool constRatio) { GdiplusStartupInput gdiplusStartupInput; ULONG_PTR gdiplusToken; GdiplusStartup(&gdiplusToken,&gdiplusStartupInput,NULL);   USES_CONVERSION; Image srcImage(A2W(srcFile)); Image *dstImage;   int srcWidth = srcImage.GetWidth(); int srcHeight = srcImage.GetHeight();   if( constRatio ){ if ( width / srcWidth < height / srcHeight ) { height = width * srcHeight / srcWidth; } else { width = height * srcWidth / srcHeight; } } dstImage = srcImage.GetThumbnailImage(width,height);   CLSID imgClsid; GetEncoderClsid(L"image/jpeg",&imgClsid); dstImage->Save(A2W(dstFile),&imgClsid,NULL);   DrawMainWindow(&srcImage,0,0); DrawMainWindow(dstImage,0,srcImage.GetHeight()+10); delete dstImage; dstImage = NULL;   //GdiplusShutdown(gdiplusToken); }

使用方法:
 

代碼如下	複製代碼
GetThumbnail("image.jpg","cc.jpg",200,80,TRUE);