체크박스 (check box)

#include <windows.h>

LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
HINSTANCE g_hInst;
LPSTR lpszClass="Check";

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance
         ,LPSTR lpszCmdParam,int nCmdShow)
{
    HWND hWnd;
    MSG Message;
    WNDCLASS WndClass;
    g_hInst=hInstance;
    
    WndClass.cbClsExtra=0;
    WndClass.cbWndExtra=0;
    WndClass.hbrBackground=(HBRUSH)(COLOR_BTNFACE+1);
    WndClass.hCursor=LoadCursor(NULL,IDC_ARROW);
    WndClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
    WndClass.hInstance=hInstance;
    WndClass.lpfnWndProc=(WNDPROC)WndProc;
    WndClass.lpszClassName=lpszClass;
    WndClass.lpszMenuName=NULL;
    WndClass.style=CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&WndClass);

    hWnd=CreateWindow(lpszClass,lpszClass,WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
        NULL,(HMENU)NULL,hInstance,NULL);
    ShowWindow(hWnd,nCmdShow);
    
    while(GetMessage(&Message,0,0,0)) {
        TranslateMessage(&Message);
        DispatchMessage(&Message);
    }
    return Message.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT iMessage,WPARAM wParam,LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    static HWND c1,c2,c3,c4;
    static BOOL ELLIPSE = FALSE;
    switch(iMessage) {
    case WM_CREATE:
        c1=CreateWindow("button","Draw Ellipse?",WS_CHILD | WS_VISIBLE |
            BS_CHECKBOX,20,20,160,25,hWnd,(HMENU)0,g_hInst,NULL);
        c2=CreateWindow("button","Good bye Message?",WS_CHILD | WS_VISIBLE |
            BS_AUTOCHECKBOX,20,50,160,25,hWnd,(HMENU)1,g_hInst,NULL);
        c3=CreateWindow("button","3State",WS_CHILD | WS_VISIBLE | BS_3STATE,
            20,80,160,25,hWnd,(HMENU)2,g_hInst,NULL);
        c4=CreateWindow("button","Auto 3State",WS_CHILD | WS_VISIBLE |
            BS_AUTO3STATE,20,110,160,25,hWnd,(HMENU)3,g_hInst,NULL);
        return 0;
    case WM_COMMAND:
        switch(LOWORD(wParam)) {
        case 0:
            if (SendMessage(c1,BM_GETCHECK,0,0)==BST_UNCHECKED) {
                SendMessage(c1,BM_SETCHECK,BST_CHECKED,0);
                ELLIPSE = TRUE;
            }
            else {
                SendMessage(c1,BM_SETCHECK,BST_UNCHECKED,0);
                ELLIPSE = FALSE;
            }
            InvalidateRect(hWnd, NULL, TRUE);
            break;
        case 2:
            if (SendMessage(c3,BM_GETCHECK,0,0)==BST_UNCHECKED)
                SendMessage(c3,BM_SETCHECK,BST_CHECKED,0);
            else
            if (SendMessage(c3,BM_GETCHECK,0,0)==BST_INDETERMINATE)
                SendMessage(c3,BM_SETCHECK,BST_UNCHECKED,0);
            else
                SendMessage(c3,BM_SETCHECK,BST_INDETERMINATE,0);
            break;
        }
        return 0;
    case WM_PAINT:
        hdc=BeginPaint(hWnd,&ps);
        if (ELLIPSE == TRUE)
            Ellipse(hdc,200,100,400,200);
        else
            Rectangle(hdc,200,100,400,200);
        EndPaint(hWnd, &ps);
        return 0;
    case WM_DESTROY:
        if (SendMessage(c2,BM_GETCHECK,0,0)==BST_CHECKED)
            MessageBox(hWnd,"Good bye","Check",MB_OK);
        PostQuitMessage(0);
        return 0;
    }
    return(DefWindowProc(hWnd,iMessage,wParam,lParam));
}