WinAPI - Zliczanie liter w tekście

#include <Windows.h>
#include <stdio.h>


enum { LITERA1, LITERA2, TEKST };



LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    static HWND  IloscLiter1, IloscLiter2, Litera1, Litera2, tekst;
    switch (msg)
    {
        case WM_CREATE:
        {
            HINSTANCE &hInstance = ((LPCREATESTRUCT)lParam)->hInstance;
            Litera1 = CreateWindowEx(0, TEXT("EDIT"), TEXT(""), WS_CHILD | WS_VISIBLE | WS_BORDER,
                110, 150, 150, 20, hwnd, (HMENU)0, hInstance, NULL);
            Litera2 = CreateWindowEx(0, TEXT("EDIT"), TEXT(""), WS_CHILD | WS_VISIBLE | WS_BORDER,
                110, 150, 150, 20, hwnd, (HMENU)1, hInstance, NULL);
            tekst = CreateWindowEx(0, TEXT("EDIT"), TEXT("Ala ma kota"), WS_CHILD | WS_VISIBLE | WS_BORDER,
                110, 150, 150, 20, hwnd, (HMENU)2, hInstance, NULL);

            IloscLiter1 = CreateWindowEx(0, TEXT("STATIC"), TEXT("0"), WS_CHILD | WS_VISIBLE | WS_BORDER,
                10, 150, 150, 20, hwnd, (HMENU)3, hInstance, NULL);
            IloscLiter2 = CreateWindowEx(0, TEXT("STATIC"), TEXT("0"), WS_CHILD | WS_VISIBLE | WS_BORDER,
                110, 150, 150, 20, hwnd, (HMENU)4, hInstance, NULL);

            SendMessage(Litera1, EM_LIMITTEXT, 1, NULL);    // ustalamy limit wprowadzanego tekstu na jeden znak
            SendMessage(Litera2, EM_LIMITTEXT, 1, NULL);
        }break;

        case WM_COMMAND:
        {
            static TCHAR znak1[2], znak2[2], _tekst[128];
            int liczbaZnakow1 = 0, liczbaZnakow2 = 0;
            TCHAR ileZnakow1[4], ileZnakow2[4];
            GetWindowText(tekst, _tekst, 127);
            switch (LOWORD(wParam))//Uzyskanie ID klikniętej kontrolki.
            {

                case LITERA1://Zaznaczenie pierwszego, odznaczenie drugiego radiobuttona:
                {

                    GetWindowText(Litera1, znak1, 2);
                    znak1[1] = 0;

                }break;
                case LITERA2://Zaznaczenie pierwszego, odznaczenie drugiego radiobuttona:
                {

                    GetWindowText(Litera2, znak2, 2);
                    znak2[1] = 0;

                }break;

                case TEKST://Zaznaczenie pierwszego, odznaczenie drugiego radiobuttona:
                {

                    GetWindowText(tekst, _tekst, 127);
                    _tekst[127] = 0;
                }break;
            };

            for (int i = 0; i < wcslen(_tekst); i++)
            {
                if (_tekst[i] == znak1[0])
                {
                    liczbaZnakow1++;
                }
                if (_tekst[i] == znak2[0])
                {
                    liczbaZnakow2++;
                }
            }
            wsprintf(ileZnakow1, TEXT("%d"), liczbaZnakow1);
            wsprintf(ileZnakow2, TEXT("%d"), liczbaZnakow2);

            SetWindowText(IloscLiter1, ileZnakow1);
            SetWindowText(IloscLiter2, ileZnakow2);

        }break;

        case WM_SIZE:
        {
            RECT windowRect;
            GetClientRect(hwnd, &windowRect);
            int static_x = (windowRect.right -100) / 2;
            int static_y = (windowRect.bottom -100) / 2;
            int edit_x = static_x + 100;
            int edit_y = static_y;

            //ustawiamy kontrolki w okienku
            MoveWindow(IloscLiter1, static_x, static_y, 70, 20, TRUE);
            MoveWindow(IloscLiter2, static_x, static_y+30, 70, 20, TRUE);
            MoveWindow(Litera1, edit_x, static_y, 70, 20, TRUE);
            MoveWindow(Litera2, edit_x, static_y + 30, 70, 20, TRUE);
            MoveWindow(tekst, edit_x - 100, static_y+60, 170, 20, TRUE);

        }break;

        case WM_CLOSE:
            if (MessageBox(NULL, TEXT("Czy na pewno chcesz zamknąć okno?"), TEXT("Pytanie"), MB_ICONQUESTION | MB_OKCANCEL) == IDOK)
                DestroyWindow(hwnd);
            break;

        case WM_DESTROY:
            PostQuitMessage(0);
            break;

        case WM_GETMINMAXINFO://Ustawianie minimalnego rozmiaru okna:
            ((MINMAXINFO *)lParam)->ptMinTrackSize.x = 300;
            ((MINMAXINFO *)lParam)->ptMinTrackSize.y = 200;
            break;

        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR ilCmdLine, int nCmdShow)
{
    WNDCLASSEX window;
    HWND hwnd = NULL;
    MSG msg;
    TCHAR ClassName[] = TEXT("KlasaOkna");
    TCHAR WindowTitle[] = TEXT("Przeliczanie");

    window.cbClsExtra = NULL;
    window.cbSize = sizeof(WNDCLASSEX);
    window.cbWndExtra = NULL;
    window.hbrBackground = (HBRUSH)(COLOR_WINDOW);
    window.hCursor = LoadCursor(NULL, IDC_ARROW);
    window.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    window.hIconSm = NULL;
    window.hInstance = hInstance;
    window.lpfnWndProc = WndProc;
    window.lpszClassName = ClassName;
    window.lpszMenuName = 0;
    window.style = CS_VREDRAW | CS_HREDRAW;

    RegisterClassEx(&window);

    hwnd = CreateWindowEx(WS_EX_WINDOWEDGE, ClassName, WindowTitle,
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT,
        400, 400, NULL, NULL, hInstance, NULL);

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    UnregisterClass(ClassName, hInstance);
    return msg.wParam;
}