identifier "hWnd" is undefined - c++

Question

I am trying to create a simple Tic-Tac-Toe game for a school project. I don't really know how to work with windows and I just want to work with others' code, using the default "Windows Desktop Application" (C++) in Visual Studio, but it keeps giving me this error message:
identifier "hWnd" is undefined
I don't really know how to work with this (at school, we work with some basic console application stuff) and I don't know how to define hWnd.
Can somebody help me?
// Proba2.cpp : Defines the entry point for the application.
//
#include <windows.h>
#include "framework.h"
#include "Proba2.h"
#define MAX_LOADSTRING 100
// Global Variables:
HINSTANCE hInst; // current instance
POINT MousePos;
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
// Initialize global strings
LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadStringW(hInstance, IDC_PROBA2, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);
// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_PROBA2));
MSG msg;
// Main message loop:
while (GetMessage(&msg, nullptr, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
//
// FUNCTION: MyRegisterClass()
//
// PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEXW wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_PROBA2));
wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_PROBA2);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassExW(&wcex);
}
//
// FUNCTION: InitInstance(HINSTANCE, int)
//
// PURPOSE: Saves instance handle and creates main window
//
// COMMENTS:
//
// In this function, we save the instance handle in a global variable and
// create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HWND hWnd;
hInst = hInstance; // Store instance handle in our global variable
hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
if (!hWnd)
{
return FALSE;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
int lepeskoz;
int hatar;
int tabla[10][10];
void kattintas(POINT mouse);
void tabla_kirajzol();
void init();
void bejeloles(int x, int y, int azonosito);
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_CREATE:
init();
return 0;
case WM_LBUTTONDOWN:
MousePos.x = LOWORD(lParam);
MousePos.y = HIWORD(lParam);
kattintas(MousePos);
return 0;
case WM_PAINT:
tabla_kirajzol();
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
UNREFERENCED_PARAMETER(lParam);
switch (message)
{
case WM_INITDIALOG:
return (INT_PTR)TRUE;
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return (INT_PTR)TRUE;
}
break;
}
return (INT_PTR)FALSE;
}
void kattintas(POINT mouse)
{
int x_adat = (mouse.x / lepeskoz);
int y_adat = (mouse.y / lepeskoz);
if (x_adat < 3 && y_adat < 3)
{
if (tabla[y_adat][x_adat] > 0) return;
}
}
void init()
{
lepeskoz = (400 - 30) / 3;
hatar = (4 * lepeskoz) + 5;
}
void bejeloles(int x, int y, int azonosito)
{
tabla[y][x] = azonosito;
tabla_kirajzol();
}
void palya()
{
int i;
PAINTSTRUCT ps;
HBRUSH hBrush;
RECT rect;
HDC hdc2;
HPEN vonalstilus;
{
vonalstilus = CreatePen(PS_SOLID, 3, RGB(0, 0, 0));
hdc2 = GetDC(hWnd);
BeginPaint(hWnd, &ps);
hBrush = CreateSolidBrush(RGB(204, 204, 204));
SetRect(&rect, 0, 0, 400, 600);
FillRect(hdc2, &rect, hBrush);
EndPaint(hWnd, &ps);
SelectObject(hdc2, vonalstilus);
for (i = 5; i < hatar; i += lepeskoz)
{
MoveToEx(hdc2, i, 5, NULL);
LineTo(hdc2, i, hatar - lepeskoz);
}
for (i = 5; i < hatar; i += lepeskoz)
{
MoveToEx(hdc2, 5, i, NULL);
LineTo(hdc2, hatar - lepeskoz, i);
}
ReleaseDC(hWnd, hdc2);
DeleteObject(vonalstilus);
}
}
void tabla_kirajzol()
{
int x;
int y;
int korx, kory, kor_szelesseg;
PAINTSTRUCT ps;
HBRUSH hBrush;
HDC hdc2;
HPEN vonalstilus;
vonalstilus = CreatePen(PS_SOLID, 3, RGB(0, 0, 0));
hBrush = CreateSolidBrush(RGB(34, 204, 204));
hdc2 = GetDC(hWnd);
BeginPaint(hWnd, &ps);
SelectObject(hdc2, vonalstilus);
palya();
for (y = 0; y < 10; ++y)
for (x = 0; x < 10; ++x)
{
korx = x * lepeskoz + 5 + (lepeskoz / 2);
kory = y * lepeskoz + 5 + (lepeskoz / 2);
kor_szelesseg = (lepeskoz / 2) - 5;
if (tabla[y][x] > 0)
{
if (tabla[y][x] == 1) {
hBrush = CreateSolidBrush(RGB(34, 204, 204)); SelectObject(hdc2, hBrush);
Ellipse(hdc2, korx - kor_szelesseg, kory - kor_szelesseg, korx + kor_szelesseg, kory + kor_szelesseg);
}
else if (tabla[y][x] == 2) {
hBrush = CreateSolidBrush(RGB(204, 204, 34)); SelectObject(hdc2, hBrush);
Rectangle(hdc2, korx - kor_szelesseg, kory - kor_szelesseg, korx + kor_szelesseg, kory + kor_szelesseg);
}
}
}
EndPaint(hWnd, &ps);
ReleaseDC(hWnd, hdc2);
DeleteObject(hBrush);
DeleteObject(vonalstilus);
}

Answer 1

bejeloles() isn't used, remove it.
Your void tabla_kirajzol(); should have this signature: void tabla_kirajzol(HWND hWnd); to enable passing the hWnd variable to the function.
Your void palya(); should, for the same reason as above, be void palya(HWND hWnd);
In the message loop, do this to pass hWnd to tabla_kirajzol:
case WM_PAINT:
tabla_kirajzol(hWnd);
break;
In tabla_kirajzol, call palya like this: palya(hWnd);
Disclaimer: The above is untested because you didn't make a Minimal, Reproducible Example, so there could be more errors