Windows提供了幾個預定義的類供我們使用，我們一般將他們叫做子視窗控制元件，簡稱控制元件；
控制元件會自己處理訊息，並在自己狀態發生改變時通知父視窗；
預定義的控制元件有：
按鈕、複選框、編輯框、靜態字串標籤和滾動條；
用效果如下的案例來來練習使用子視窗控制元件：

/*-------------------------------
MyWindows.c
---------------------------------*/
#include <Windows.h>
#include <Strsafe.h>

#define IDC_EDIT_1 0x100
#define IDC_BUTTON_1 0x101
#define IDC_BUTTON_2  0x102

HINSTANCE g_hInstance;

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

int WINAPI WinMain(HINSTANCE hInstance,	//入口函式,WINAPI即是__stdcall(函式呼叫約定的一種)
	HINSTANCE hPrevInstance,
	PSTR szCmdLine,
	int iCmdShow)
{
	g_hInstance = hInstance;
	static TCHAR szAppName[] = TEXT("MyWindows");//定義視窗類的名字
	HWND hwnd;	//視窗控制代碼定義
	MSG msg; //定義訊息
	WNDCLASS wndclass; //Windows類定義

	wndclass.cbClsExtra = 0;
	wndclass.cbWndExtra = 0;
	//背景,先要得到畫刷控制代碼傳回
	wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);//游標
	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);//圖示
	wndclass.hInstance = g_hInstance;//模組控制代碼,如前面說的.exe .dll等地址
	wndclass.lpfnWndProc = WndProc;//過程函式
	wndclass.lpszClassName = szAppName;	//類名
	wndclass.lpszMenuName = NULL;//選單
	wndclass.style = CS_HREDRAW | CS_VREDRAW;//調整寬度和高度重新繪製視窗

	if (!RegisterClass(&wndclass)){ //填完視窗類註冊該視窗類
		MessageBox(NULL, TEXT("此程式需要在Windows NT平臺上執行!"), 
			szAppName, MB_ICONERROR);
		return 0;
	}
 	//建立視窗並設定其具體特徵,返回視窗控制代碼,視窗類名
	hwnd = CreateWindow(szAppName,
		TEXT("Win模板"),		   //視窗標題
		WS_OVERLAPPEDWINDOW,     //類風格的擴充套件
		CW_USEDEFAULT,           //初始視窗座標
		CW_USEDEFAULT,
		600,
		500,
		NULL,	//有無父視窗
		NULL,	//有無選單
		g_hInstance,
		NULL
		);
	ShowWindow(hwnd, iCmdShow);//顯示視窗
	UpdateWindow(hwnd);	//更新視窗
	while (GetMessage(&msg, NULL, 0, 0)){
		TranslateMessage(&msg);	//翻譯訊息
		DispatchMessage(&msg);	//派送訊息到系統,系統再呼叫WinProc函式處理訊息
	}
	return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, 
	LPARAM lParam)//傳入訊息結構體的前四個引數
{
	TCHAR szOutBuffer[0x80] = {0};
	//StringCchPrintf(szOutBuffer, 0x80, TEXT("訊息：%x\n"), message);
	//OutputDebugString(szOutBuffer);//用來看產生什麼訊息

	switch (message)
	{
	case WM_CREATE:
		CreateWindow(TEXT("EDIT"),	//文字框
			NULL,							
			WS_CHILD | WS_VISIBLE | WS_VSCROLL | ES_MULTILINE,	
			0,								
			0,
			500,
			500,
			hwnd,										
			IDC_EDIT_1,
			g_hInstance,
			NULL
			);
		CreateWindow(TEXT("BUTTON"),	//按鈕
			TEXT("設定"),
			WS_CHILD | WS_VISIBLE,
			520,
			380,
			60,
			30,
			hwnd,										
			IDC_BUTTON_1,
			g_hInstance,
			NULL
			);
		CreateWindow(TEXT("BUTTON"),	//按鈕
			TEXT("獲取"),
			WS_CHILD | WS_VISIBLE,
			520,
			420,
			60,
			30,
			hwnd,
			IDC_BUTTON_2,
			g_hInstance,
			NULL
			);
		return 0;
	case WM_COMMAND:
		switch (LOWORD(wParam))
		{
		case IDC_BUTTON_1:
			SetDlgItemText(hwnd, IDC_EDIT_1, TEXT("測試"));
			return 0;
		case IDC_BUTTON_2:										
			GetDlgItemText(hwnd, IDC_EDIT_1, szOutBuffer, 0x80);
			MessageBox(hwnd, szOutBuffer, TEXT("讀到資料"), MB_OK);
			return 0;
		}
		return 0;
	case WM_DESTROY:	//點選右上角關閉傳送WM_DESTROY訊息
		PostQuitMessage(0);
		return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}