这是《C／C++程序员实用大全》上面的源码

				#include 
				
				LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
				{
				   switch (uMsg)
				   {
				         case WM_CREATE:  // Set current directory to value passed on command line.
				         {
				               char   szMessage[MAX_PATH + 31];
				               char   szCommandLine[MAX_PATH + 1];
				               LPTSTR lpToken = NULL;
				               LPTSTR lpszDirName = NULL;
				               DWORD  dwcCurDir = MAX_PATH;
				
				               lstrcpy( szCommandLine, GetCommandLine() );
				               // Search for extra input after program name.
				               if ( ( lpToken = strstr( szCommandLine, " " ) ) )
				               {
				                  // Get first argument by itself, if there is one.
				                  lpszDirName = strtok( lpToken, " " );
				                  if ( lpszDirName )
				                  {
				                     // Use lpTemp pointer to isolate 1st arg.
				                     LPTSTR lpTemp = strstr(lpszDirName, " ");
				                     if (lpTemp)
				                        *lpTemp = 0;
				                     // Attempt to change the current directory.
				                     if ( !SetCurrentDirectory(lpszDirName) )
				                        wsprintf( szMessage,
				                                  "Cannot set current directory to [%s]",
				                                  lpszDirName );
				                     else
				                        wsprintf( szMessage, "Set current directory to [%s]",
				                                  lpszDirName );
				                     // Report result of operation.
				                     MessageBox( hWnd, szMessage,
				                                 "Result of SetCurrentDirectory()", MB_OK );
				                  }
				               }
				         }
				         return DefWindowProc( hWnd, uMsg, wParam, lParam );
				
				         case WM_COMMAND:
				               switch ( LOWORD( wParam ) )
				               {
				                     case IDM_TEST:
				                     {
				                           char szBuffer[MAX_PATH + 1];
				                           DWORD dwcNameSize = MAX_PATH + 1;
				
				                           // Now query the system for the paths.
				                           GetCurrentDirectory( dwcNameSize, &szBuffer );
				                           MessageBox( hWnd, szBuffer, "Current Directory", MB_OK );
				                     }
				                     break;
				                     case IDM_EXIT:
				                           DestroyWindow( hWnd );
				                           break;
				               }
				               break;
				         case WM_DESTROY:
				               PostQuitMessage( 0 );
				               break;
				         default:
				               return (DefWindowProc(hWnd, uMsg, wParam, lParam));
				   }
				   return (NULL);
				}