How do I create a second window within a callback procedure? Win32 - c++

Question

I'm trying to create a second window if a dialog box from my first window returns a certain way. Unfortunately, if I call CreateWindowEx() from within the callback process of the first window, it doesn't recognise the second window's HWND. I also tried defining the first window in WinMain and making it visible within the callback, but it failed to recognise the HWND once again. Am I trying to do this wrong, or am I just missing something?
Edit:
#include "stdafx.h"
#include "md5.h"
#include "Coursework.h"
#include "accounts.h"
const char g_szClassName[] = "myMainWindow";
const char g_szLoggedInClass[] = "loggedInWindow";
#define IDC_CREATE_ACCOUNT 101
#define IDC_LOG_IN 110
MYSQL *conn;
static std::string strUserName;
BOOL CALLBACK CreateDlgProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
switch(Message)
{
case WM_INITDIALOG:
return TRUE;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDOK:
{
CreateAccount(hwnd);
}
break;
case IDCANCEL:
EndDialog(hwnd, IDCANCEL);
break;
}
default:
return FALSE;
}
}
BOOL CALLBACK LogInDlgProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
switch(Message)
{
case WM_INITDIALOG:
return TRUE;
case WM_COMMAND:
switch(LOWORD(wParam))
{
case IDCANCEL:
EndDialog(hwnd, IDCANCEL);
break;
case IDOK:
{
if(bLogIn(hwnd, strUserName))
{
EndDialog(hwnd, IDOK);
}
}
break;
}
break;
default:
return FALSE;
}
}
LRESULT CALLBACK LoggedInProc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CLOSE:
DestroyWindow(hwnd);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CLOSE:
PostQuitMessage(0);
break;
case WM_CREATE:
{
if (*mysql_error(conn)) //Checks if the connection succeeded, and
{ //exits the program if false.
MessageBox(hwnd, "No connection to the server could be established.\r\nPlease contact your administrator.", "Error", MB_ICONERROR);
exit(-1);
}
HWND hCreateButton = CreateWindowEx(NULL, "Button", "Create account", WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON, 500, 250, 120, 24, hwnd, (HMENU)IDC_CREATE_ACCOUNT, GetModuleHandle(NULL), NULL);
HWND hLogInButton = CreateWindowEx(NULL, "Button", "Log in", WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON, 500, 210, 120, 24, hwnd, (HMENU)IDC_LOG_IN, GetModuleHandle(NULL), NULL);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDC_CREATE_ACCOUNT:
{
int ret = DialogBox(GetModuleHandle(NULL), MAKEINTRESOURCE(IDD_DIALOG1), hwnd, CreateDlgProc);
if (ret == -1)
{
MessageBox(hwnd, "Dialog failed to appear", "Error", MB_OK | MB_ICONINFORMATION);
}
}
break;
case IDC_LOG_IN:
{
int ret = DialogBox(GetModuleHandle(NULL), MAKEINTRESOURCE(IDD_DIALOG2), hwnd, LogInDlgProc);
if(ret == -1)
{
MessageBox(hwnd, "Dialog failed to appear", "Error", MB_OK | MB_ICONINFORMATION);
}
else if(ret == IDOK)
{
ShowWindow(hwnd, SW_HIDE);
}
}
}
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
WNDCLASSEX wc2;
HWND hwnd;
HWND hLoggedIn;
MSG Msg;
conn = mysql_init(NULL); //Initialises mySQL connection
mysql_real_connect(conn, "localhost", "root", "SecurityRules", "coursework", 0, NULL, 0);
//Registering the Window Class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
//Registering the second Window Class
wc2.cbSize = sizeof(WNDCLASSEX);
wc2.style = 0;
wc2.lpfnWndProc = LoggedInProc;
wc2.cbClsExtra = 0;
wc2.cbWndExtra = 0;
wc2.hInstance = hInstance;
wc2.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc2.hCursor = LoadCursor(NULL, IDC_ARROW);
wc2.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc2.lpszMenuName = NULL;
wc2.lpszClassName = g_szLoggedInClass;
wc2.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if(!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!\r\nContact your administrator.", "Error!", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
if(!RegisterClassEx(&wc2))
{
MessageBox(NULL, "Window Registration failed!\r\nContact your administrator.", "Error!", MB_ICONEXCLAMATION|MB_OK);
return 0;
}
//Creating the main Window
hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, g_szClassName, "Coursework", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 1080, 640, NULL, NULL, hInstance, NULL);
hLoggedIn = CreateWindowEx(WS_EX_CLIENTEDGE, g_szLoggedInClass, "Coursework", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 1080, 640, NULL, NULL, hInstance, NULL);
if(hwnd == NULL)
{
MessageBox(NULL, "Window Creation Failed!\r\nContact your adminstrator.", "Error!", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
mysql_close(conn);
return Msg.wParam;
}
}
Edit 2:
Intellisense (I'm in Visual Studio) states that 'identifier hLoggedIn is undefined', as well as nCmdShow.