Insert a program into a windows window. h in C

Question

I have this code in C using the windows. h library for creating a simple window. How to implement a program so that it appears inside this window.

#include <windows.h>

const char g_szClassName[] = "ClassedaJanela";

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
    case WM_CLOSE:
        DestroyWindow(hwnd);
    break;
    case WM_DESTROY:
        PostQuitMessage(0);
    break;
    default:
        return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;

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);

if(!RegisterClassEx(&wc))
{
    MessageBox(NULL, "Window Registration Failed!", "Error!",
        MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

hwnd = CreateWindowEx(
    WS_EX_CLIENTEDGE,
    g_szClassName,
    "Simple Window",
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT, 240, 120,
    NULL, NULL, hInstance, NULL);

if(hwnd == NULL)
{
    MessageBox(NULL, "Window Creation Failed!", "Error!",
        MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

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

// Step 3: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
    TranslateMessage(&Msg);
    DispatchMessage(&Msg);
}
return Msg.wParam;
}

Answer 1

First, you need to define what you want to put in the window. It is recommended that you use some Forms editor (Visual Studio with Win32, Codeblocks with wxwidgets, Qt, etc). In these editors you create the Form and add the buttons and controls and then you can define some function for them.