能编译成功，但什么都不显示！

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

int CDECL MessageBoxPrintf(TCHAR *szCaption, TCHAR *szFormat, ...)
{
    TCHAR szBuffer[1024];
    va_list pArgList;
    va_start(pArgList, szFormat);
    _vsntprintf(szBuffer, sizeof(szBuffer) / sizeof(TCHAR), szFormat, pArgList);
    va_end(pArgList);
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
    int cxScreen, cyScreen;
    cxScreen = GetSystemMetrics(SM_CXSCREEN);
    cyScreen = GetSystemMetrics(SM_CYSCREEN);
    MessageBoxPrintf(TEXT("ScrnSize"), TEXT("The screen is %i pixels wide by %i pixels high. "), cxScreen, cyScreen);
    return 0;
}