[핵심 API로 배우는 윈도우프로그래밍(강경우, 한빛아카데미)] 3장 6번 풀이

#include <Windows.h>
#include<tchar.h>
#include<string.h>
#include<math.h>
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam);
 
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow)
{
    HWND hwnd;
    MSG msg;
 
    WNDCLASS WndClass;
    WndClass.style = CS_HREDRAW | CS_VREDRAW;
    WndClass.lpfnWndProc = WndProc;
    WndClass.cbClsExtra = 0;
    WndClass.cbWndExtra = 0;
    WndClass.hInstance = hInstance;
    WndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    WndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    WndClass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    WndClass.lpszMenuName = NULL;
    WndClass.lpszClassName = _T("Window Class Name");
 
    RegisterClass(&WndClass); //윈도우 클래스를 커널에 등록
 
    hwnd = CreateWindow( //윈도우 핸들값 반환
        _T("Window Class Name"), //윈도우 클래스 이름
        _T("홍길동의 첫 번째 윈도우"), //윈도우 타이틀이름
        WS_OVERLAPPEDWINDOW, //윈도우 스타일
        100, //윈도우 위치 x좌표
        100,//윈도우 위치 y좌표
        1000, //윈도우 가로크기
        700, //윈도우 세로크기
        NULL, //부모 윈도우핸들
        NULL, //메뉴핸들
        hInstance, //응용프로그램 인스턴스
        NULL); //생성 윈도우 정보
 
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
 
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    HPEN hPen, oldPen;
    static RECT catRect = { 100,100,150,150 };
    static RECT ratRect;
    static bool isClick = false;
    static float m = 0;
    switch (iMsg)
    {
    case WM_CREATE:
        break;
 
    case WM_KEYDOWN:
        break;
    case WM_LBUTTONDOWN:
        isClick = true;
        ratRect = { LOWORD(lParam),HIWORD(lParam),LOWORD(lParam) + 20,HIWORD(lParam) + 20 };
        InvalidateRgn(hwnd, NULL, TRUE);
        SetTimer(hwnd, 1, 10, NULL);
        break;
    case WM_MOUSEMOVE:
        hdc = GetDC(hwnd);
        if (isClick)
        {
            ratRect = { LOWORD(lParam),HIWORD(lParam),LOWORD(lParam) + 20,HIWORD(lParam) + 20 };
            InvalidateRgn(hwnd, NULL, TRUE);
        }
        ReleaseDC(hwnd, hdc);
        break;
    case WM_LBUTTONUP:
        isClick = false;
        InvalidateRgn(hwnd, NULL, TRUE);
        break;
    case WM_TIMER:
        if (isClick)
        {
            catRect.right = catRect.left + 50;
            catRect.bottom = catRect.top + 50;
 
            if (ratRect.left > catRect.left)
                catRect.left += 1;
            else
                catRect.left -= 1;
 
            if (ratRect.top > catRect.top)
                catRect.top += 1;
            else
                catRect.top -= 1;
            InvalidateRgn(hwnd, NULL, TRUE);
        }
        break;
 
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        DrawText(hdc, _T("고양이"), _tcslen(_T("고양이")), &catRect, DT_CENTER | DT_VCENTER);
        if (isClick)
            DrawText(hdc, _T("쥐"), _tcslen(_T("쥐")), &ratRect, DT_CENTER | DT_VCENTER);
 
        EndPaint(hwnd, &ps);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
 
    }
    return DefWindowProc(hwnd, iMsg, wParam, lParam);
}