从最小的LoadPic开始（IPICTURE接口）。。
参考原型：
微软的loadpic.exe，
下载地址：http://support.microsoft.com/kb/218972
我能做到的最小的LoadPic:
#include <windows.h>
#include <olectl.h>
LPPICTURE gpPicture;
HWND hWnd;
HDC hDC;
long hmWidth,hmHeight;
int SrcX,SrcY;
LRESULT CALLBACK MainWndProc(HWND, UINT,WPARAM, LPARAM);
void LoadPictureFile(char* point);
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)
{
MSG msg;
WNDCLASS wndclass;
wndclass.style = 0;
wndclass.cbClsExtra = 0;
wndclass.cbWndExtra = 0;
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndclass.lpszMenuName = NULL;
hInstance=GetModuleHandle(NULL);
wndclass.hInstance = hInstance;
wndclass.hIcon = NULL;
wndclass.lpfnWndProc = MainWndProc;
wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW);
wndclass.lpszClassName = "MyWindowClass";
RegisterClass (&wndclass);
hWnd = CreateWindow ("MyWindowClass","LoadPic",
WS_MAXIMIZEBOX|WS_MINIMIZEBOX|WS_SYSMENU|WS_SIZEBOX,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL,NULL,hInstance,NULL);
hDC = GetDC(hWnd);
ShowWindow(hWnd, SW_SHOWNORMAL);
while (GetMessage(&msg, NULL, 0, 0))
{
DispatchMessage(&msg);
}
return 0;
}
void LoadPictureFile(char* point)
{
char szPath[255];
OLECHAR wszPath[255];
int i,j;
if (gpPicture)
{
gpPicture->Release();
}
i=0;
j=0;
do
{
szPath[j]=point[i];
if(szPath[j]=='\\')
{
j++;
szPath[j]='\\';
}
i++;
j++;
}while(point[i-1]!='\0');
MultiByteToWideChar(CP_ACP, 0, szPath, -1, wszPath, 255);
OleLoadPicturePath(wszPath, 0, 0, 0, IID_IPicture, (LPVOID *)&gpPicture);
gpPicture->get_Width(&hmWidth);
gpPicture->get_Height(&hmHeight);
SrcX=hmWidth*GetDeviceCaps(hDC, LOGPIXELSX)/2540;
SrcY=hmHeight*GetDeviceCaps(hDC, LOGPIXELSY)/2540;
InvalidateRect(hWnd,NULL,1);
}
LRESULT CALLBACK MainWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
PAINTSTRUCT ps;
OPENFILENAME ofn;
char szFileName[255];
switch (message)
{
case WM_RBUTTONUP:
szFileName[0]='\0';
ofn.lStructSize=sizeof(OPENFILENAME);
ofn.hwndOwner=hWnd;
ofn.hInstance=0;
ofn.lpstrFilter="JPG Files (*.jpg)\0*.jpg\0";
ofn.lpstrCustomFilter=0;
ofn.nMaxCustFilter=0;
ofn.nFilterIndex=0;
ofn.lpstrFile=szFileName;
ofn.nMaxFile=MAX_PATH;
ofn.lpstrFileTitle=0;
ofn.nMaxFileTitle=MAX_PATH;
ofn.lpstrInitialDir=0;
ofn.lpstrTitle=0;
ofn.Flags=OFN_HIDEREADONLY|OFN_PATHMUSTEXIST;
ofn.nFileOffset=0;
ofn.nFileExtension=0;
ofn.lpstrDefExt=NULL;
ofn.lCustData=0;
ofn.lpfnHook=0;
ofn.lpTemplateName=0;
if (GetOpenFileName(&ofn))
{
LoadPictureFile(szFileName);
}
break;
case WM_PAINT:
BeginPaint(hWnd, &ps);
if (gpPicture)
{
gpPicture->Render(hDC, 0, 0, SrcX, SrcY, 0, hmHeight, hmWidth, -hmHeight, NULL);
}
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
ExitProcess(0);
break;
default:
return DefWindowProc (hWnd, message, wParam, lParam);
}
return 0;
}
VC6编译后大小：2032字节，连2K都不到。
源程序
