Qt day4

简单时钟：

widget.h:

#ifndef WIDGET_H
#define WIDGET_H
 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
 
 
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);
  //自定义槽函数
  void timer_slot();
 
 
private:
    Ui::Widget *ui;
 
    QTimer *timer;
 
    QPen pen;
 
    int second;
    int minute;
    int hour;
 
};
#endif // WIDGET_H

 widget.cpp:

#include "widget.h"
#include "ui_widget.h"
 
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    //定时器实例化对象
    timer = new QTimer(this);
    connect(timer,&QTimer::timeout,this,&Widget::timer_slot);
    //启动定时器
    timer->start(1000);
}
 
Widget::~Widget()
{
    delete ui;
}
 
void Widget::timer_slot(){
 
    QDateTime time = QDateTime::currentDateTime();
 
    QString t = time.toString("hh:mm:ss");
 
    //提取时间
    QStringList t1 = t.split(":");
 
    hour = t1[0].toUInt();
    minute = t1[1].toUInt();
    second = t1[2].toUInt();
 
    update();
}
 
void Widget::paintEvent(QPaintEvent *event){
    //定义一个马良
    QPainter painter(this);
    //抗锯齿
    painter.setRenderHint(QPainter::Antialiasing);
    //定义一个画笔
    pen.setWidth(3);
    pen.setColor(Qt::green);
    //马良用这个笔
    painter.setPen(pen);
    painter.setFont(QFont("楷体",18));
    //粉刷填充颜色
    QBrush back(QColor("skyblue"));
    painter.setBrush(back);
    //设置画笔起始位置
    painter.translate(this->width()/2,this->height()/2);
    //画个圆
    painter.drawEllipse(QPoint(0,0),200,200);
 
    //开始画刻度线
    int val = 6;
    //先转30度从小的开始画
    painter.rotate(30);
    for(int i = 0;i<60;i++){
 
        //再设置一个笔
        pen.setWidth(2);
        pen.setColor(QColor("popur"));
        painter.setPen(pen);
        //总共60个刻度，每过四个小的一个大的,大刻度要写上数字
        if(val%5 == 1){
            painter.drawLine(QPoint(0,-200),
                             QPoint(0,-180));
 
            val++;
        }
        else{
 
            painter.drawLine(QPoint(0,-200),
                             QPoint(0,-190));
            val++;
        }
        //每次偏移6度
        painter.rotate(6);
    }
    //转回来
    painter.rotate(-30);
    //时针
    pen.setWidth(5);
    pen.setColor(QColor("purple"));
    pen.setStyle(Qt::SolidLine);
    painter.setPen(pen);
    painter.rotate(hour*30+(minute*6+6*second/60)/12);
    painter.drawLine(QPoint(0,0),QPoint(0,-50));
    painter.rotate(-(hour*30+minute*6/12+6*second/60/12));
 
    //分针
    pen.setWidth(4);
    pen.setColor(QColor("blue"));
    pen.setStyle(Qt::SolidLine);
    painter.setPen(pen);
    painter.rotate(minute*6+second/10);
    painter.drawLine(QPoint(0,-100),QPoint(0,0));
    painter.rotate(-(minute*6+second/10));
 
    //秒钟
    pen.setWidth(3);
    pen.setColor(QColor("green"));
    pen.setStyle(Qt::SolidLine);
    painter.setPen(pen);
    painter.rotate(6*second);
    painter.drawLine(QPoint(0,-140),QPoint(0,0));
 
 
 
 
 
}