创建窗口步骤：
（1）注册窗口类（RegisterClassEx）
（2）创建窗口（CreateWindowEx）
（3）在桌面显示窗口（ShowWindow）
（4）更新窗口客户区（UpdateWindow）
（5）进入无限的消息获取和处理的循环：获取消息（GetMessage）;分派消息至窗口函数处理（DisPatchMessage）;
如果是WM_QUIT,函数（GetMessage）返回False,消息循环结束，程序退出。
注册窗口类需要初始化一个窗口类结构，将其写成一个函数如下：
ATOM MyRegisterClass(HINSTANCE hInstance) { WNDCLASSEXW wcex; //窗口类结构 wcex.cbSize = sizeof(WNDCLASSEX); //结构大小 wcex.style = CS_HREDRAW | CS_VREDRAW|CS_OWNDC;//CS:class style此窗口类派生的窗口具有的风格 //CS_OWNDC使得windows将每次对DC的设置保存下来，CS_HREDRAW | CS_VREDRAW窗口大小变化就刷新 wcex.lpfnWndProc = WndProc; //窗口函数指针 wcex.cbClsExtra = 0; //紧跟在窗口类结构后的附加字节数 wcex.cbWndExtra = 0; //紧跟在窗口事例后的附加字节数 wcex.hInstance = hInstance;//本模块的实例句柄 wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_CLOCKWINDOW));//窗口左上角图标句柄 wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);//光标句柄 wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW); //背景画刷句柄 wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_CLOCKWINDOW);//菜单名 //wcex.lpszMenuName =NULL; //无菜单 wcex.lpszClassName = szWindowClass; //此窗口类名 wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));//小图标句柄 return RegisterClassExW(&wcex); //注册此窗口类 }
创建窗口、显示窗口、刷新客户区写成一个函数如下：
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow) { hInst = hInstance; // 将实例句柄存储在全局变量中 HWND hWnd = CreateWindowW(szWindowClass, //窗口类名 szTitle, //窗口标题 WS_OVERLAPPEDWINDOW, //窗口风格 WS:window style CW_USEDEFAULT, //初始位置X坐标 CW_USEDEFAULT, //初始位置Y坐标 500, //宽度 500, //高度 nullptr, //父窗口句柄 nullptr, //菜单句柄 hInstance, //程序实例句柄 nullptr); //用户数据 if (!hWnd) { return FALSE; } ShowWindow(hWnd, nCmdShow); //显示窗口 UpdateWindow(hWnd); //刷新客户区 return TRUE; }
因此主函数可以写为：
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int APIENTRY wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPWSTR lpCmdLine, _In_ int nCmdShow) { UNREFERENCED_PARAMETER(hPrevInstance); UNREFERENCED_PARAMETER(lpCmdLine); // 初始化全局字符串 LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING); LoadStringW(hInstance, IDC_CLOCKWINDOW, szWindowClass, MAX_LOADSTRING); MyRegisterClass(hInstance); // 执行应用程序初始化: if (!InitInstance (hInstance, nCmdShow)) { return FALSE; } HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_CLOCKWINDOW)); MSG msg; // 主消息循环: while (GetMessage(&msg, nullptr, 0, 0))//GetMessage返回False程序结束 { if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) { TranslateMessage(&msg); DispatchMessage(&msg); } } return (int) msg.wParam; //程序结束时返回最后一个MSG的wParam。 }
在窗口作图
测试一：先打开notepad，之后运行此代码
HWND hWnd; HDC hDC; hWnd = ::FindWindow(_TEXT("Notepad"), NULL); hDC = ::GetDC(hWnd); while (::IsWindow(hWnd)) { ::SetTextColor(hDC, RGB(255, 0, 0)); ::SetBkColor(hDC, RGB(0, 0, 0)); ::TextOut(hDC, 10, 10, _T("this is a test."), sizeof("this is a test.") - 2); HPEN hPen = CreatePen(NULL,4,RGB(255,255,255)); ::SelectObject(hDC, hPen); ::SelectObject(hDC, ::GetStockObject(BLACK_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); ::SelectObject(hDC, ::GetStockObject(WHITE_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); ::SelectObject(hDC, ::GetStockObject(LTGRAY_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); ::SelectObject(hDC, ::GetStockObject(GRAY_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); ::SelectObject(hDC, ::GetStockObject(DKGRAY_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); ::SelectObject(hDC, ::GetStockObject(DKGRAY_BRUSH)); Ellipse(hDC, 0, 0, 500, 500); Sleep(1000); } ReleaseDC(hWnd, hDC);
绘图首先要取得设备环境句柄
PAINTSTRUCT ps; HDC hdc = BeginPaint(hWnd, &ps); //取得（窗口客户区无效区域）设备环境句柄 //绘图代码 //EndPaint(hWnd, &ps); HDC hdcW = ::GetWindowDC(hWnd); //取得整个窗口设备环境句柄 HDC hdcD = ::GetDC(hWnd); //取得窗口客户区设备环境句柄(函数可用在任何地方)
接着有时为了作图方便需要修改默认坐标系
void SetIsotropic(HWND hWnd,HDC hdc) { RECT rect; GetClientRect(hWnd, &rect); //取得客户区大小 ::SetMapMode(hdc, MM_ANISOTROPIC); //自定义坐标系MM_ANISOTROPIC：X!=Y,MM_ISOTROPIC:X=Y ::SetWindowExtEx(hdc, 500, 500, NULL); //逻辑刻度，第四个参数可用于返回原来的大小 ::SetViewportExtEx(hdc, rect.right, -rect.bottom, NULL); //像素刻度(坐标方向)，第四个参数可用于返回原来的大小 ::SetViewportOrgEx(hdc, rect.right / 2, rect.bottom / 2, NULL); //修改坐标系(参照之前坐标系的位置坐标)，第四个参数可用于返回原来的原点 }
修改完坐标系后开始绘制时钟表面
void paintClock(HWND hWnd,HDC hdc) { HPEN hPenTri, hPenTime, hPenCent; HBRUSH hBrushTr, hBrushTime, hBrushCent; int colorUseR = (rand() % (255 - 0 + 1)) + 0; //(rand() % (b-a+1))+ a; a~b随机数 int colorUseG = (rand() % (255 - 0 + 1)) + 0; int colorUseB = (rand() % (255 - 0 + 1)) + 0; hPenTri = CreatePen(NULL, 4, RGB(255, colorUseG, 240)); hBrushTr = ::CreateSolidBrush(RGB(255, colorUseG, 240)); bankColor = RGB(255, colorUseG, 240); hPenTime = CreatePen(NULL, 4, RGB(colorUseR, 240, 240)); hBrushTime = ::CreateSolidBrush(RGB(colorUseR, 240, 240)); hPenCent = ::CreatePen(NULL, 4, RGB(240, 240, colorUseB)); hBrushCent = ::CreateSolidBrush(RGB(240, 240, colorUseB)); SetIsotropic(hWnd,hdc); ///三角形//////////////////////////////////////////////////////////////////////////////////// //SetDCBrushColor(hdc, RGB(255, 255, 255));//（无效） ::SelectObject(hdc, hPenTri); ::SelectObject(hdc, hBrushTr); //POINT Mypoint[12] = { (250,10),(375,33.5),(466.5,125),(490,250),(466.5,375),(375,466.5),(250,490),(125,466.5),(33.5,375),(10,250),(33.5,125),(125,33.5) };//写法错误 POINT Mypoint[12] = { 0,240,120,207.84,207.84,120,240,0,207.84,-120,120,-207.84,0,-240,-120,-207.84,-207.84,-120,-240,0,-207.84,120,-120,207.84 }; //::ClientToScreen(hWnd, point); //投射到屏幕坐标,返回至point POINT Mypoint1[3] = { Mypoint[0],Mypoint[4],Mypoint[8] }; POINT Mypoint2[3] = { Mypoint[1],Mypoint[5],Mypoint[9] }; POINT Mypoint3[3] = { Mypoint[2],Mypoint[6],Mypoint[10] }; POINT Mypoint4[3] = { Mypoint[3],Mypoint[7],Mypoint[11] }; //POINT Mypoint5[4]={ Mypoint1 ,Mypoint2,Mypoint3,Mypoint4}//不好用for循环简化操作，二维数组用不了？？ Polygon(hdc, Mypoint1, 3); Polygon(hdc, Mypoint2, 3); Polygon(hdc, Mypoint3, 3); Polygon(hdc, Mypoint4, 3); //圆形=============================================================== ::SelectObject(hdc, hPenTime); ::SelectObject(hdc, hBrushTime);//图形填充色 for (int i = 0; i < 12; i++) { Ellipse(hdc, Mypoint[i].x - 10, Mypoint[i].y - 10, Mypoint[i].x + 10, Mypoint[i].y + 10); } //中心点加文本======================================================= ::SelectObject(hdc, hPenCent); ::SelectObject(hdc, hBrushCent); ::Ellipse(hdc, -5, 5, 5, -5); ::SetTextColor(hdc, RGB(0, 0, 0)); //文字颜色 //::SetBkColor(hdc, TRANSPARENT); //文字背景色，设置为透明无效 ::SetBkMode(hdc, TRANSPARENT); //文字背景透明 CString strText = _T("时钟"); TextOut(hdc, -240, 240, (LPCWSTR)strText, sizeof(strText) - 2); }
绘制时钟的指针函数
void DrawHand(HDC hdc, int nLength, int nWidth, int nDegrees, COLORREF clrColor) { double nRadians = (double)nDegrees * 2 * 3.1415926 / 360; POINT pt[2]; pt[0].x = (int)(nLength*sin(nRadians)); pt[0].y = (int)(nLength*cos(nRadians)); pt[1].x = pt[0].x /-5; pt[1].y = pt[0].y /-5; HPEN hPen = ::CreatePen(PS_SOLID, nWidth, clrColor); HPEN oldPen = (HPEN)::SelectObject(hdc, hPen); ::MoveToEx(hdc, pt[0].x, pt[0].y, NULL); LineTo(hdc, pt[1].x, pt[1].y); ::SelectObject(hdc, oldPen); ::DeleteObject(hPen); }
在窗口函数WM_CREATE下设置定时器
case WM_CREATE: //当一个应用程序通过CreateWindowEx函数或者CreateWindow函数请求创建窗口时发送此消息，(此消息在函数返回之前发送)。 SYSTEMTIME time; ::GetLocalTime(&time); s_PreHour = time.wHour%12;//取余 s_PreMinute = time.wMinute; s_PreSecond = time.wSecond; SetTimer(hWnd, //窗口句柄 IDT_CLOCK,//TimerID 1000, //间隔 NULL); //计时器函数指针 return 0; //它应当返回0以使得窗口的创建过程得以继续。如果对于这个消息程序返回-1，窗口将会被销毁。 //并且CreateWindowEx或者CreateWindow函数将会返回一个值为NULL的句柄。
在WM_TIMER下控制指针的变化与重画
case WM_TIMER: paintClock(hWnd, hDC); //paintClock(hWnd, hDC);重画了时钟面板，使得覆盖了旧的时钟指针 if (::IsIconic(hWnd)) //如果窗口是最小化 { return 0; } ::GetLocalTime(&time); //HDC hDC = ::GetDC(hWnd);//(无法写在这里) SetIsotropic(hWnd, hDC);//建立坐标系 if (time.wMinute != s_PreMinute) { //DrawHand(hDC, 140, 8, s_PreHour * 30 + s_PreMinute / 2, bankColor);//使用时钟面板颜色覆盖原指针 //DrawHand(hDC, 170, 6, s_PreMinute * 6, bankColor); //覆盖失败（不能使得指针颜色完全消失，如同在相同的两点好几条画好几条线，看起来线条变粗并不像一条直线） s_PreHour = time.wHour; s_PreMinute = time.wMinute; } if (time.wSecond != s_PreSecond) { //DrawHand(hDC, 170, 1, s_PreSecond * 6, bankColor);//使用时钟面板颜色覆盖原指针 DrawHand(hDC, 80, 6, s_PreHour * 30 + s_PreMinute / 2, RGB(0,0,0)); DrawHand(hDC, 120, 4, s_PreMinute * 6, RGB(0, 0, 0)); DrawHand(hDC, 170, 2, s_PreSecond * 6, RGB(0, 0, 0)); s_PreSecond = time.wSecond; } //::MessageBeep(MB_ICONASTERISK);//发出“嘟嘟”声 break;
效果图
