[핵심 API로 배우는 윈도우프로그래밍(강경우, 한빛아카데미)] 2장 1~5번 풀이

#include <Windows.h>
#include<tchar.h>
#include<string.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); 
 
    hwnd = CreateWindow( 
        _T("Window Class Name"), 
        _T("홍길동의 첫 번째 윈도우"), 
        WS_OVERLAPPEDWINDOW,
        200, 
        300,
        1000, 
        1000, 
        NULL, 
        NULL, 
        hInstance,
        NULL); 
 
    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;
    RECT rect = { 0,0,1000,1000 };
    static TCHAR str[10][100];
    static int count,yPos,lengh[10];
    static SIZE size;
 
 
    switch (iMsg)
    {
    case WM_CREATE:
        count = 0;
        yPos = 0;
        CreateCaret(hwnd, NULL, 5, 15);    
        ShowCaret(hwnd);                
        break;
    case WM_CHAR:
        if (yPos != 10)
        {
            if (wParam == VK_RETURN&&count >= 0 && count <= 99)
            {
                str[yPos][count] = '\0';
                yPos++;
                count = 0;
            }
            else if (wParam == VK_BACK)
            {
                if (count > 0)
                {
                    count--;
                    str[yPos][count] = NULL;
                }
                else if (count == 0)
                {
                    yPos--;
                    count = _tcsclen(str[yPos]);
                    count--;
                    str[yPos][count] = NULL;
                }
            }
            else
            {
                str[yPos][count++] = wParam;
                //str[yPos][count] = '\0';
            }
            if (count == 100)
            {
                str[yPos][count] = '\0';
                yPos++;
                count = 0;
            }
        }
                                     
        InvalidateRgn(hwnd, NULL, TRUE);
        break;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        for(int i=0;i<=yPos;i++)
            TextOut(hdc, 0, i*20, str[i], _tcslen(str[i]));
        GetTextExtentPoint(hdc, str[yPos], _tcslen(str[yPos]), &size);
        SetCaretPos(size.cx, yPos * 20);
        EndPaint(hwnd, &ps);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        DestroyCaret();
        HideCaret(hwnd);
        DestroyCaret();
        break;
    }
    return DefWindowProc(hwnd, iMsg, wParam, lParam);
}