[핵심 API로 배우는 윈도우프로그래밍(강경우, 한빛아카데미)] 10장 1번 풀이

#include <Windows.h>
#include<tchar.h>
#include<string.h>
#include<winres.h>
#include<process.h>
#include<time.h>
#include<stdio.h>
#include<stdlib.h>
#pragma comment(linker,"/entry:WinMainCRTStartup /subsystem:console")
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam);
void ThreadProc();
HINSTANCE hInst;
HWND hwnd;
 
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow)
{
    MSG msg;
    WNDCLASS WndClass;
 
    hInst = hInstance;
    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("박정호"),
        WS_OVERLAPPEDWINDOW,
        50,
        50,
        1000,
        700,
        NULL,
        NULL,
        hInstance,
        NULL);
 
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
 
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}
#define MAX_THREAD_NUM 50
int XPOS, YPOS;
int r, g, b;
LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    PAINTSTRUCT ps;
    static HANDLE hThread[MAX_THREAD_NUM];
    static int count = 0;
    static RECT rt;
 
    switch (iMsg)
    {
    case WM_CREATE:
        GetClientRect(hwnd, &rt);
        break;
 
    case WM_LBUTTONDOWN:
        XPOS = rand() % rt.right;
        YPOS = rand() % rt.bottom;
        r = rand() % 256;
        g = rand() % 256;
        b = rand() % 256;
        hThread[count] = (HANDLE)_beginthreadex(NULL, 0, (unsigned int(__stdcall *)(void *))ThreadProc, NULL, 0, NULL);
        count++;
        break;
    case WM_DESTROY:
        for (int i = 0; i < MAX_THREAD_NUM; i++)
            CloseHandle(hThread[i]);
        PostQuitMessage(0);
        break;
 
    }
    return DefWindowProc(hwnd, iMsg, wParam, lParam);
}
void ThreadProc()
{
    HDC hdc;
    //srand(time(NULL));
    int xPos, yPos;
 
    hdc = GetDC(hwnd);
    xPos = XPOS;
    yPos = YPOS;
    SelectObject(hdc, CreateSolidBrush(RGB(r, g, b)));
    Ellipse(hdc, xPos - 10, yPos - 10, xPos + 10, yPos + 10);
    for (int i = 0; i < 10; i++)
    {
        Sleep(1000);
        Ellipse(hdc, xPos - 10, yPos - 10, xPos + 10, yPos + 10);
        SelectObject(hdc, CreateSolidBrush(RGB(rand() % 256, rand() % 256, rand() % 256)));
        
        
 
 
    }
    ReleaseDC(hwnd, hdc);
    return;
}