C / C++ / MFC

typedef BOOL (WINAPI *MYOPENFILENAME)(HWND, LPTSTR, LPTSTR);<br />
<br />
typedef BOOL (WINAPI *MYGETSAVEFILENAME)(HWND, LPTSTR, LPTSTR);

MYOPENFILENAME myFunc1;<br />
<br />
    HMODULE hPong=::LoadLibrary("ipong.dll");<br />
<br />
if(hPong)<br />
{<br />
//dynamic load the function<br />
   myFunc1=(MYOPENFILENAME)::GetProcAddress(hPong,"MyGetOpenFileName");<br />
<br />
        if(myFunc1)<br />
         {<br />
         //call the function<br />
         (myFunc1)();<br />
<br />
         }<br />
<br />
}

BOOL __stdcall MyGetOpenFileName(HWND, LPTSTR, LPTSTR);<br />
BOOL __stdcall MyGetSaveFileName(HWND, LPTSTR, LPTSTR);

<br />
if(myFunc1)<br />
{<br />
  //call the function<br />
  // I get lost here :(<br />
  (myFunc1)();<br />
}<br />

///////////////////////////////////////////////////////////////////////////
#include <windows.h>
///////////////////////////////////////////////////////////////////////////
// We'll define the file pointers as types, it's a great help for us and
// the compiler.
typedef BOOL (__stdcall * MYGETOPENFILENAME)(HWND ghWnd, LPTSTR szName, 
                                               LPTSTR szInitDir);
///////////////////////////////////////////////////////////////////////////
// This is the actual function pointer that we have to set before use.
MYGETOPENFILENAME MyGetOpenFileName;
///////////////////////////////////////////////////////////////////////////
// A function to show a windows error message.
static void ShowLastError()
{
	LPVOID lpMsgBuf;
	if (!FormatMessage( 
		FORMAT_MESSAGE_ALLOCATE_BUFFER | 
		FORMAT_MESSAGE_FROM_SYSTEM | 
		FORMAT_MESSAGE_IGNORE_INSERTS,
		NULL,
		GetLastError(),
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
		(LPTSTR) &lpMsgBuf,
		0,
		NULL ))
	{
	   // Handle the error.
	   return;
	}

	// Process any inserts in lpMsgBuf.
	// ...

	// Display the string.
	MessageBox( NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK | MB_ICONERROR );

	// Free the buffer.
	LocalFree( lpMsgBuf );
}
///////////////////////////////////////////////////////////////////////////
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, 
                     LPSTR lpCmdLine, int nShowCmd)
{
	// The filename buffer.
	TCHAR		filename[MAX_PATH];

	// Getting a handle to the dll.
	HMODULE		hDll = LoadLibrary(TEXT("ipong.dll"));	

	// Testing if we got a valid handle.
	if (NULL != hDll)
	{
		// Then we initializes our function pointer.
		MyGetOpenFileName = (MYGETOPENFILENAME) GetProcAddress(hDll, TEXT("MyGetOpenFileName"));

		// Testing if we found the function.
		if (NULL != MyGetOpenFileName)
		{
			lstrcpy(filename, TEXT("test.txt"));

			// Let's try it then...
			if(MyGetOpenFileName(NULL, filename, TEXT("C:\\")))
			{
				MessageBox(NULL, filename, TEXT("Testing"), MB_OK);
			}
		}
		else
		{
			ShowLastError();
		}


		// Cleaning up.
		FreeLibrary(hDll);
	}
	else
	{
		ShowLastError();
	}

	return 0;
}
///////////////////////////////////////////////////////////////////////////

HDC dc = GetDC(NULL);
int x = GetDeviceCaps(dc, LOGPIXELSX);
int y = GetDeviceCaps(dc, LOGPIXELSY);
ReleaseDC(dc);