Qt实现画时钟，获取系统时间，url文件下载这些内容

#include "MyClock.h" #include <qvboxlayout> #include <qpainter.h> #include <QTime> #include <qtimer.h> #include <qmath.h> MyClock::MyClock(QWidget* parent) : QWidget(parent) { QTimer* timer = new QTimer(this); connect(timer, SIGNAL(timeout()), this, SLOT(update())); timer->start(1000); QVBoxLayout* verticalLayout = new QVBoxLayout(this); verticalLayout->setSpacing(0); verticalLayout->setContentsMargins(0, 0, 0, 0); //MyPushButton* btn = new MyPushButton(this); //btn->setText("按钮1"); //verticalLayout->addWidget(btn); //ui.setupUi(this); } MyClock::~MyClock() {} QRectF textRectF(double radius, int pointSize, double angle) { QRectF rectF; rectF.setX(radius * qCos(angle * M_PI / 180.0) - pointSize * 2); rectF.setY(radius * qSin(angle * M_PI / 180.0) - pointSize); rectF.setWidth(pointSize * 4); rectF.setHeight(pointSize * 2); return rectF; } void MyClock::paintEvent(QPaintEvent* ev) { Q_UNUSED(ev); // 时针、分针、秒针位置,三顶点定义一个多边形 static const QPoint hourHand[3] = { QPoint(7, 8), QPoint(-7, 8), QPoint(0, -30) }; static const QPoint minuteHand[3] = { QPoint(7, 8), QPoint(-7, 8), QPoint(0, -65) }; static const QPoint secondHand[3] = { QPoint(7, 8), QPoint(-7, 8), QPoint(0, -80) }; // 时针、分针、秒针颜色 QColor hourColor(200, 100, 0, 200); QColor minuteColor(0, 127, 127, 150); QColor secondColor(0, 160, 230, 150); int side = qMin(width(), height()); QTime time = QTime::currentTime(); QPainter painter(this); //绘制的图像反锯齿 painter.setRenderHint(QPainter::Antialiasing); // 平移坐标系原点至中心点 painter.translate(width() / 2, height() / 2); // 缩放 painter.scale(side / 200.0, side / 200.0); // 绘制时针 painter.setPen(Qt::NoPen); painter.setBrush(hourColor); //保存当前状态，与下面的store配对使用。 painter.save(); // 每圈360° = 12h 即：旋转角度 = 小时数 * 30° painter.rotate(30.0 * ((time.hour() + time.minute() / 60.0))); //填充指针区域 painter.drawConvexPolygon(hourHand, 3); //恢复之前保存的状态 painter.restore(); painter.setPen(hourColor); // 绘制小时线 （360度 / 12 = 30度） for (int i = 0; i < 12; ++i) { painter.drawLine(88, 0, 96, 0); painter.rotate(30.0); } int radius = 100; QFont font = painter.font(); font.setBold(true); painter.setFont(font); int pointSize = font.pointSize(); // 绘制小时文本 int nHour = 0; for (int i = 0; i < 12; ++i) { nHour = i + 3; if (nHour > 12) nHour -= 12; painter.drawText(textRectF(radius * 0.8, pointSize, i * 30), Qt::AlignCenter, QString::number(nHour)); } // 绘制分针 painter.setPen(Qt::NoPen); painter.setBrush(minuteColor); painter.save(); // 每圈360° = 60m 即：旋转角度 = 分钟数 * 6° painter.rotate(6.0 * (time.minute() + time.second() / 60.0)); painter.drawConvexPolygon(minuteHand, 3); painter.restore(); painter.setPen(minuteColor); // 绘制分钟线 （360度 / 60 = 6度） for (int j = 0; j < 60; ++j) { if ((j % 5) != 0) painter.drawLine(92, 0, 96, 0); painter.rotate(6.0); } // 绘制秒针 painter.setPen(Qt::NoPen); painter.setBrush(secondColor); painter.save(); // 每圈360° = 60s 即：旋转角度 = 秒数 * 6° painter.rotate(6.0 * time.second()); painter.drawConvexPolygon(secondHand, 3); painter.restore(); }