ウインドウにエディットボックスを付ける。

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

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <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);

#define ID_BUTTON1 100 
#define ID_EDIT 200 

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    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;
    }

    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);

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

    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;
 int    wmId, wmEvent;
    HDC hdc;
    TCHAR greeting[] = _T("Hello, World!");
 static HWND  hButton,hEdit;

    switch (message)
    {
 case WM_CREATE://ウインドウ作成時の処理
  //ボタンの作成
  hButton = CreateWindowEx(0, TEXT("BUTTON"), TEXT("Button1"),
   WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
   100, 0, 100, 30,
   hWnd,
   (HMENU)ID_BUTTON1, 
   (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
   NULL);
  //エディットボックスの作成
  hEdit = CreateWindowEx(WS_EX_CLIENTEDGE, // 拡張ウィンドウスタイル
   TEXT("EDIT"),
   TEXT("ここに入力\r\n"),
   WS_CHILD | WS_VISIBLE | WS_HSCROLL |
   WS_VSCROLL | ES_LEFT | ES_MULTILINE |
   ES_AUTOHSCROLL | ES_AUTOVSCROLL ,
   0, 0,
   LOWORD(lParam), HIWORD(lParam),
   hWnd,
   (HMENU)ID_EDIT,
   hInst,
   NULL);

  SetFocus(hEdit);

  break;
 case WM_SIZE://ウインドウのサイズが変わったとき（ウインドウ初回生成時も）に実行
  MoveWindow(hEdit, 0, 30, LOWORD(lParam), HIWORD(lParam), TRUE);
  break;
    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);
        break;
 case WM_COMMAND:
  wmId = LOWORD(wParam);
  wmEvent = HIWORD(wParam);
  switch (wmId)
  {
  case ID_BUTTON1://ボタンが押された時の処理

   MessageBox(0,0,0,0);
   break;
  }
  
  break;
    
 case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
        break;
    }

    return 0;
}