Windows Programming Basics

Windows HelloWorld Example

`` // GT_HelloWorldWin32.cpp // compile with: /D_UNICODE /DUNICODE /DWIN32 /D_WINDOWS /c

include <windows.h>

include <stdlib.h>

include <string.h>

include <tchar.h>

[RK] Win32 API definitions in windows.h, UNICODE definitions in tchar.h

// Global variables

// The main window class name. static TCHAR szWindowClass[] = _T(“win32app”);

// The string that appears in the application’s title bar. static TCHAR szTitle[] = _T(“Win32 Guided Tour Application”);

HINSTANCE hInst;

// Forward declarations of functions included in this code module: LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); [RK] Window procedure function, a GUI event handler

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) [RK] Entry point for any Win32 Application { WNDCLASSEX 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_APPLICATION));
wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName   = NULL;
wcex.lpszClassName  = szWindowClass;
wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_APPLICATION));

if (!RegisterClassEx(&wcex))
{
    MessageBox(NULL,
        _T("Call to RegisterClassEx failed!"),
        _T("Win32 Guided Tour"),
        NULL);

    return 1;
}

[RK] WinMain() initializes structure WNDCLASSEX (Window Properties) and registers it with OS using RegisterClassEx().

hInst = hInstance; // Store instance handle in our global variable

// The parameters to CreateWindow explained:
// szWindowClass: the name of the application
// szTitle: the text that appears in the title bar
// WS_OVERLAPPEDWINDOW: the type of window to create
// CW_USEDEFAULT, CW_USEDEFAULT: initial position (x, y)
// 500, 100: initial size (width, length)
// NULL: the parent of this window
// NULL: this application does not have a menu bar
// hInstance: the first parameter from WinMain
// NULL: not used in this application
HWND hWnd = CreateWindow(
    szWindowClass,
    szTitle,
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT,
    500, 100,
    NULL,
    NULL,
    hInstance,
    NULL
);

if (!hWnd)
{
    MessageBox(NULL,
        _T("Call to CreateWindow failed!"),
        _T("Win32 Guided Tour"),
        NULL);

    return 1;
}

// The parameters to ShowWindow explained:
// hWnd: the value returned from CreateWindow
// nCmdShow: the fourth parameter from WinMain
ShowWindow(hWnd,
    nCmdShow);
UpdateWindow(hWnd);

[RK] Then create a Window using CreateWindow(), and display it using ShowWindow() and UpdateWindow()

// Main message loop:
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}

[RK] Finally, continuously loop in GUI event dispatcher. Dispatches GUI events to event handler – WndProc()

return (int) msg.wParam;

}

// // FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM) // // PURPOSE: Processes messages for the main window. // // 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) { PAINTSTRUCT ps; HDC hdc; TCHAR greeting[] = _T(“Hello, World!”);

switch (message)
{
case WM_PAINT:
    hdc = BeginPaint(hWnd, &ps);

    // Here your application is laid out.
    // For this introduction, we just print out "Hello, World!"
    // in the top left corner.
    TextOut(hdc,
        5, 5,
        greeting, _tcslen(greeting));
    // End application-specific layout section.

    EndPaint(hWnd, &ps);

[RK] WM_PAINT, called to update display window (with contents). All UI logic should be guarded between BeginPaint() and EndPaint().

    break;
case WM_DESTROY:
    PostQuitMessage(0);

[RK] WM_DESTROY, called to Quit the current Window.

    break;
default:
    return DefWindowProc(hWnd, message, wParam, lParam);
    break;
}

return 0;

} ``

Windows Debugging - MS Help Guide

(http://msdn.microsoft.com/en-us/library/windows/hardware/ff551063%28v=vs.85%29.aspx)

Tools included: UMDH - User Mode Dump Heap. Analyzes heap memory allocations for a process. For each allocation, display size of allocation, size of overhead, pointer to allocation, and allocation stack. Done for all active heaps used by a process.

Standard Debugging Techniques:

Mostly microsoft specific debugger usage and know-how stuff. No general debugging techniques mentioned.