源代码;

#include "stdafx.h"
#include "GDIDemoWindowsOfBrush.h"

#include <time.h>                   // 新增：时间函数，用于产生随机数种子
#pragma comment(lib,"winmm.lib")    // 新增：调用PlaySound函数所需库文件

#define WINDOW_WIDTH    800
#define WINDOW_HEIGHT   600
#define WINDOW_TITLE    L"【Windows窗口测试——GDI练习】"


//-----------------------------------【全局变量声明部分】-------------------------------------
//  描述：全局变量的声明
//------------------------------------------------------------------------------------------------
HDC         g_hdc = NULL;                                                                                               // 新增：全局设备环境句柄
HPEN        g_hPen[7] = { 0 };                                                                                          // 新增：定义画笔句柄的数组
HBRUSH      g_hBrush[7] = { 0 };                                                                                        // 新增：定义画刷句柄的数组
int         g_iPenStyle[7] = { PS_SOLID,PS_DASH,PS_DOT,PS_DASHDOT,PS_DASHDOTDOT,PS_NULL,PS_INSIDEFRAME };               // 新增：定义画笔样式数组并初始化
int         g_iBrushStyle[6] = { HS_VERTICAL,HS_HORIZONTAL,HS_CROSS,HS_DIAGCROSS,HS_FDIAGONAL,HS_BDIAGONAL };           // 新增：定义画刷样式数组并初始化


LRESULT     CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
BOOL        Game_Init(HWND hwnd);
VOID        Game_Paint(HWND hwnd);
BOOL        Game_CleanUp(HWND hwnd);

//-----------------------------------【WinMain( )函数】--------------------------------------
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    WNDCLASSEX wndClass = { 0 };
    wndClass.cbSize = sizeof(WNDCLASSEX);
    wndClass.style = CS_HREDRAW | CS_VREDRAW;
    wndClass.lpfnWndProc = WndProc;
    wndClass.cbClsExtra = 0;
    wndClass.cbWndExtra = 0;
    wndClass.hInstance = hInstance;
    wndClass.hIcon = (HICON)::LoadImage(NULL, L"icon.ico", IMAGE_ICON, 0, 0, LR_DEFAULTSIZE | LR_LOADFROMFILE);
    wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndClass.hbrBackground = (HBRUSH)GetStockObject(GRAY_BRUSH);
    wndClass.lpszMenuName = NULL;
    wndClass.lpszClassName = L"ForTheDreamOfGameDevelop";


    if (!RegisterClassEx(&wndClass))
        return -1;


    HWND hwnd = CreateWindow(L"ForTheDreamOfGameDevelop",
        WINDOW_TITLE,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        WINDOW_WIDTH,
        WINDOW_HEIGHT,
        NULL,
        NULL,
        hInstance,
        NULL);


    MoveWindow(hwnd, 250, 80, WINDOW_WIDTH, WINDOW_HEIGHT, true);
    ShowWindow(hwnd, nShowCmd);
    UpdateWindow(hwnd);

    
    if (!Game_Init(hwnd))
    {
        MessageBox(hwnd, L"资源初始化失败", L"消息窗口", 0);
        return FALSE;
    }

    MSG msg = { 0 };
    while (msg.message != WM_QUIT)
    {
        if (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    UnregisterClass(L"ForTheDreamOfGameDevelop", wndClass.hInstance);
    return 0;
}


//-----------------------------------【WndProc( )函数】--------------------------------------
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT paintStruct;                //定义一个PAINTSTRUCT结构体来记录一些绘制信息

    switch (message)                        //switch语句开始
    {
    case WM_PAINT:                          // 若是客户区重绘消息
        g_hdc = BeginPaint(hwnd, &paintStruct);     //指定窗口进行绘图工作的准备，并用将和绘图有关的信息填充到paintStruct结构体中。
        Game_Paint(hwnd);
        EndPaint(hwnd, &paintStruct);       //EndPaint函数标记指定窗口的绘画过程结束
        ValidateRect(hwnd, NULL);           // 更新客户区的显示
        break;                              //跳出该switch语句

    case WM_KEYDOWN:
        if (wParam == VK_ESCAPE)
            DestroyWindow(hwnd);
        break;

    case WM_DESTROY:                        //若是窗口销毁消息
        Game_CleanUp(hwnd);                 //调用自定义的资源清理函数Game_CleanUp（）进行退出前的资源清理
        PostQuitMessage(0);                 //向系统表明有个线程有终止请求。用来响应WM_DESTROY消息
        break;                              //跳出该switch语句

    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }

    return 0;
}

//-----------------------------------【Game_Init( )函数】--------------------------------------
//  描述：初始化函数，进行一些简单的初始化
//------------------------------------------------------------------------------------------------
BOOL Game_Init(HWND hwnd)               // 新增：环境句柄和随机函数，用于随机随机初始化画笔和画刷的颜色值
{
    g_hdc = GetDC(hwnd);                //获取设备环境句柄
    srand((unsigned)time(NULL));        //用系统时间初始化随机种子 

    //随机初始化画笔和画刷的颜色值
    for (int i = 0; i <= 6; i++)
    {
        g_hPen[i] = CreatePen(g_iPenStyle[i], 1, RGB(rand() % 256, rand() % 256, rand() % 256));        // 使用传统取余方法来进行RGB的选取
        if (i == 6)
            g_hBrush[i] = CreateSolidBrush(RGB(rand() % 256, rand() % 256, rand() % 256));
        else
            g_hBrush[i] = CreateHatchBrush(g_iBrushStyle[i], RGB(rand() % 256, rand() % 256, rand() % 256));
    }

    Game_Paint(hwnd);
    ReleaseDC(hwnd, g_hdc);
    return TRUE;
}

//-----------------------------------【Game_Paint( )函数】--------------------------------------
//  描述：绘制函数，在此函数中进行绘制操作
//--------------------------------------------------------------------------------------------------
VOID Game_Paint(HWND hwnd)
{
    //定义一个y坐标值
    int y = 0;

    //一个for循环，用7种不同的画笔绘制线条
    for (int i = 0; i <= 6; i++)
    {
        y = (i + 1) * 70;

        SelectObject(g_hdc, g_hPen[i]);         //将对应的画笔选好
        MoveToEx(g_hdc, 1, y, NULL);            //“光标”移动到对应的（30，y）坐标处
        LineTo(g_hdc, 100, y);                  //从（30，y）坐标处向（100，y）绘制线段
    }

    /*注意上面画完后y=420，下面画矩形的时候还有用*/
    //定义两个x坐标值
    int x1 = 120;
    int x2 = 190;

    //用7种不同的画刷填充矩形
    for (int i = 0; i <= 6; i++)
    {
        SelectObject(g_hdc, g_hBrush[i]);       //选用画刷
        Rectangle(g_hdc, x1, 70, x2, y);        //画出一个封闭的矩形，矩形左上角坐标为（x1,50），右下角坐标为（x2，y）
        x1 += 90;
        x2 += 90;
    }
}

//-----------------------------------【Game_CleanUp( )函数】--------------------------------
//  描述：资源清理函数，在此函数中进行程序退出前资源的清理工作
//---------------------------------------------------------------------------------------------------
BOOL Game_CleanUp(HWND hwnd)
{
    //一个for循环，释放掉所有的画笔和画刷句柄
    for (int i = 0; i <= 6; i++)
    {
        DeleteObject(g_hPen[i]);
        DeleteObject(g_hBrush[i]);
    }
    return TRUE;
}