RandomNumberPicker

#include <windows.h>
#include <ctime>
#include <stdio.h>
#include "resource.h"

#define ID_BUTTON 1
#define ID_EDIT 2

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
static HWND hwndEdit;
static HWND hwndLabel;
void CenterWindow(HWND);
int GetRandomNumber(int passedNumber);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow) {
        srand(time(NULL));
        MSG  msg;
        WNDCLASSW wc = {0};
        wc.lpszClassName = L"RNP";
        wc.hInstance     = hInstance;
        wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
        wc.lpfnWndProc   = WndProc;
        wc.hIcon         = LoadIcon(GetModuleHandle(NULL), MAKEINTRESOURCE(IDI_MYICON));
        wc.hCursor       = LoadCursor(0, IDC_ARROW);
        RegisterClassW(&wc);
        CreateWindowW(wc.lpszClassName, L"RNP", WS_OVERLAPPEDWINDOW|WS_VISIBLE, 260, 134, 265, 134, 0, 0, hInstance, 0);
        while (GetMessage(&msg, NULL, 0, 0)) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        return (int) msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    static wchar_t *max =  L"Entrez la borne maximale :";
    static wchar_t *responce =  L"1";
    HWND hwndButton;
    switch(msg) {
    case WM_KEYDOWN:
        if (wParam == VK_ESCAPE) {
            int ret = MessageBoxW(hwnd, L"Etes vous sur de vouloir quitter?",
                L"Message", MB_OKCANCEL);
            if (ret == IDOK) {
                SendMessage(hwnd, WM_CLOSE, 0, 0);
            }
        }
        break;
    case WM_CREATE:
        hwndButton=CreateWindowW(L"Button", L"Generer", WS_VISIBLE|WS_CHILD, 98, 37, 62, 21, hwnd, (HMENU)ID_BUTTON, NULL, NULL);
        CenterWindow(hwnd);
        CreateWindowW(L"Static", max, WS_CHILD|WS_VISIBLE|SS_LEFT, 10, 12, 197, 30, hwnd, (HMENU)1, NULL, NULL);
        hwndLabel=CreateWindowW(L"Static", L"", WS_CHILD|WS_VISIBLE|SS_LEFT, 116, 68, 50, 30, hwnd, (HMENU)1, NULL, NULL);
        hwndEdit=CreateWindowW(L"Edit", NULL, WS_CHILD|WS_VISIBLE|WS_BORDER, 195, 9, 40, 23, hwnd, (HMENU)ID_EDIT, NULL, NULL);
        break;
    case WM_COMMAND:
        if (LOWORD(wParam)==ID_BUTTON) {
            int number = 0;
            TCHAR buff[1024];
            char str[256];
            GetWindowText(hwndEdit, buff, 1024);
            number = GetRandomNumber(atoi(buff));
            sprintf_s(str, "%d", number);
            SetWindowText(hwndLabel, str);
            RedrawWindow(hwndLabel, NULL, NULL, RDW_ERASE);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    }
    return DefWindowProcW(hwnd, msg, wParam, lParam);
}

void CenterWindow(HWND hwnd) {
    RECT rc = {0};
    GetWindowRect(hwnd, &rc);
    int win_w = rc.right - rc.left;
    int win_h = rc.bottom - rc.top;
    int screen_w = GetSystemMetrics(SM_CXSCREEN);
    int screen_h = GetSystemMetrics(SM_CYSCREEN);
    SetWindowPos(hwnd, HWND_TOP, (screen_w - win_w)/2, (screen_h - win_h)/2, 0, 0, SWP_NOSIZE);
}

int GetRandomNumber(int passedNumber)
{
    int min, max, number = 0;
    min=1;
    if(passedNumber!=0)
    {
        max=passedNumber;
    }
    else
    {
        max=10;
    }
    number = rand()%(max-min)+min;
    /*char str[256];
    sprintf_s(str, "%d", number);
    OutputDebugString(buff);*/
    return number;
}