9月11日qt - 技术栈

使用Qt绘画事件处理画一个闹钟

头文件

cpp 复制代码

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QPainter>
#include <QTime>
#include <QTimer>
#include <QTimerEvent>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void paintEvent(QPaintEvent *event)override;

public slots:
    void timeout_slot();
private:
    Ui::Widget *ui;
    QTimer t1;
    int tid=0;
    int hou1;//小时
    int min1;//分
    int sec1;//秒

};
#endif // WIDGET_H

源文件

cpp 复制代码

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    t1.start(1000);
    //timeout信号与槽函数链接
    connect(&t1,&QTimer::timeout,this,&Widget::timeout_slot);
}

Widget::~Widget()
{
    delete ui;
}
//槽函数
void Widget::timeout_slot()
{
    update();
//    QPaintEvent *Q=nullptr;
//    this->paintEvent(Q);
}
//绘制事件处理函数
void Widget::paintEvent(QPaintEvent *event)
{
    QTime sysTime=QTime::currentTime();
    QString t=sysTime.toString("hh:mm:ss");//转换为字符串
        QStringList tlist =t.split(":"); //以 ：分割t

        hou1 =tlist[0].toUInt(); //将小时传化为无符号整数
        min1 =tlist[1].toUInt(); //将分钟传化为无符号整数
        sec1 =tlist[2].toUInt(); //将秒传化为无符号整数
    QPainter painter(this);//实例一个画家
    //准备画笔
    QPen pen;
    pen.setStyle(Qt::SolidLine);
    pen.setColor(QColor("purple"));
    pen.setWidth(5);

    //字体
    QFont font;
    font.setFamily("楷体");
    font.setPointSize(10);
    //给画家
    painter.setPen(pen);
    painter.translate(this->width()/2,this->height()/2);//设置画家起点
    painter.drawEllipse(QPoint(0,0),250,250);//绘制一个圆

    pen.setColor(QColor("black"));
    painter.setPen(pen);
    //画刻度
    for(int i=1;i<=60;i++)
    {
        painter.rotate(6);
        if(i%5!=0)
        {
            pen.setWidth(3);
            painter.setPen(pen);
            painter.drawLine(0,242,0,250);
        }
        else
        {
            pen.setWidth(6);
            painter.setPen(pen);
            painter.drawLine(0,235,0,250);
            painter.drawText(QRect(-10,-220,20,20),Qt::AlignCenter,QString::number(i/5));
        }
    }
    //时针
    painter.save();
    pen.setColor(QColor("red"));
    pen.setWidth(15);
    painter.setPen(pen);
    painter.rotate(hou1*30+(min1/60)*6+sec1/10);
    painter.drawLine(0,-5,0,-80);
    painter.restore();
    //分钟
    painter.save();
    pen.setColor(QColor("blue"));
    pen.setWidth(10);
    painter.setPen(pen);
    painter.rotate(min1*6+sec1/60*6);
    painter.drawLine(0,-5,0,-120);
    painter.restore();
    //秒针
    painter.save();
    pen.setColor(QColor("yellow"));
    pen.setWidth(5);
    painter.setPen(pen);
    painter.rotate(sec1*6);
    painter.drawLine(0,-5,0,-180);
    painter.restore();
}