Win32 API Reference

The Win32 API (Application Programming Interface) is a set of functions and data types that provide access to the features of the Microsoft Windows operating system. It's the primary interface for developing native Windows applications.

Core Functions

Essential functions for managing resources, memory, and basic system operations.

Window Management

Functions for creating, managing, and interacting with windows, dialogs, and controls.

Graphics and Multimedia

APIs for drawing, image manipulation, and multimedia playback.

System Services

Interacting with system processes, services, and configuration.

Example: Creating a Basic Window

Demonstrates the fundamental steps to create a simple window using Win32 API.

A typical window creation involves:

  1. Defining a Window Class (WNDCLASS)
  2. Registering the Window Class
  3. Creating the Window (CreateWindowEx)
  4. The Message Loop

Sample Code Snippet:

// Include necessary headers
#include <windows.h>

LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow )
{
// Register the window class.
const char CLASS_NAME[] = "Sample Class";

WNDCLASS wc = { };

wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.lpszClassName = CLASS_NAME;

RegisterClass(&wc);

// Create the window.
HWND hwnd = CreateWindowEx(
0, // Optional window styles.
CLASS_NAME, // Window class
"Learn Win32 API", // Window text
WS_OVERLAPPEDWINDOW | WS_VISIBLE, // Window style
CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, // Size and position
NULL, // Parent window
NULL, // Menu
hInstance, // Instance handle
NULL // Additional application data
);

if (hwnd == NULL)
{
return 0;
}

// Run the message loop.
MSG msg = { };
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}

return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
case WM_DESTROY:
PostQuitMessage(0);
return 0;

case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd, &ps);
// All painting occurs here, between BeginPaint and EndPaint.
FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW+1));
EndPaint(hwnd, &ps);
}
return 0;
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}