Qt学习之旅---2.绘图，时钟小例子

时间：2022-03-14 00:30:01

学习笔记，小白可以相互学习，大佬看到能告诉咱理解不对的地方就好了。


/*********.h**********************************/
#ifndef WIDGET_H
#define WIDGET_H

#include<QWidget>
#include<QPaintEvent>
#include<QPainter>
#include<QPen>
#include<QTimer>
#include<iostream>
#include<QLabel>

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = 0);
    ~Widget();
protected:
    void paintEvent(QPaintEvent *event)
    {
        setFixedSize(500,500);
        static int i = 0;
        QPainter ppp(this);//定义一个画家
        QPen p(QColor(Qt::red));//画笔，颜色红
        p.setWidth(4);//粗细10

        ppp.setPen(p);//画家拿到笔
        ppp.translate(200,200);//移动中心点(移动画家的中心点位置)

        //ppp.drawEllipse(QPoint(0,0),100,100);//以画家为中心点，画椭圆
        ppp.rotate(i*6);//转多少度，参数为转的度数
        i++;
        ppp.drawLine(0,0,0,-160);//画线
        //ppp.drawText(0,0,"小可爱");

        static int j = 0;
        QPainter ppp1(this);
        QPen p1(QColor(Qt::blue));
        p1.setWidth(4);
        ppp1.setPen(p1);
        ppp1.translate(200,200);
        ppp1.rotate(j*0.5);
        j++;
        ppp1.drawLine(0,0,0,-120);

        static int k = 0;
        QPainter ppp3(this);
        QPen p3(QColor(Qt::green));
        p3.setWidth(6);
        ppp3.setPen(p3);
        ppp3.translate(200,200);
        ppp3.rotate(k*0.25/60);
        k++;
        ppp3.drawLine(0,0,0,-80);

        QPainter ppp4(this);
        QPen p4(QColor(Qt::black));
        p4.setWidth(4);
        ppp4.setPen(p4);
        ppp4.translate(200,200);
        ppp4.drawEllipse(QPoint(0,0),190,190);

        QPainter ppp2(this);
        QPen p2(QColor(Qt::black));
        p2.setWidth(20);
        ppp2.setPen(p4);
        ppp2.translate(200,200);
        ppp2.drawPoint(0,0);

        QPainter ppp5(this);
        QPen p5(QColor(Qt::black));
        p5.setWidth(2);
        ppp5.setPen(p5);
        ppp5.translate(350,350);
        ppp5.translate(rand()%20,rand()%20);
        ppp5.drawPixmap(0,0,QPixmap("ooopic_1504102052.ico"));
//        ppp5.scale(0,0);//放大

        QPainter ppp6(this);
        QPen p6(QColor(Qt::black));
        p6.setWidth(4);
        ppp6.setPen(p6);
        ppp6.translate(200,200);
        int a;
        QString b;
        for(a = 0; a < 12 ;a++)
        {
            b = QString::number(a);
            ppp6.drawLine(0,-180,0,-190);
            ppp6.drawText(0,-165,b);
            ppp6.rotate(30);
        }

        QPainter ppp7(this);
        QPen p7(QColor(Qt::blue));
        p7.setWidth(2);
        ppp7.setPen(p7);
        ppp7.translate(200,200);
        for(a = 0; a < 60 ;a++)
        {
            ppp7.drawLine(0,-183,0,-190);
            ppp7.rotate(6);
        }

        // 求时间数字
        sec = i%60 - 1;
        min = i/60%60;
        hour = i/3600%24;
        std::cout<<":"<<hour<<" :"<<min<<" :"<<" :"<<sec<<std::endl;

        QString x,y,z;
        x = QString::number(hour);
        y = QString::number(min);
        z = QString::number(sec);

        QPainter ppp8(this);
        QPen p8(QColor(Qt::red));
        p8.setWidth(30);
        ppp8.setPen(p8);
        ppp8.translate(0,480);
        ppp8.drawText(0,0,x);
        ppp8.drawText(20,0," : ");
        ppp8.drawText(40,0,y);
        ppp8.drawText(60,0," : ");
        ppp8.drawText(80,0,z);

    }
public slots:
    void paint()
    {
        update();//人工调用
    }


private:
    QTimer *time;
    int sec,min,hour;
    QLabel *lab;
};

#endif // WIDGET_H


/********.cpp**********************************/
#include "widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    time = new QTimer;
    time->start(1000);

    connect(time,SIGNAL(timeout()),SLOT(paint()));

}

Widget::~Widget()
{

}


小时钟：

实现了鼠标键盘滚轮事件改变其时间


/********myclock.h*****************************/

#ifndef MYCLOCK_H
#define MYCLOCK_H

#include <QObject>
#include <QWidget>
#include <QTimer>

class myclock : public QWidget
{
    Q_OBJECT
public:
    explicit myclock(QWidget *parent = nullptr);

signals:

public slots:
    void setvalue(int);
    void paint()
    {
        update();
    }
protected:
    void paintEvent(QPaintEvent *event);

private:
//    int pos;
    int s;
    QTimer *time;
};

#endif // MYCLOCK_H

/*************widget.h***************************************/ 

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include<QSlider>
#include"myclock.h"
#include<QMouseEvent>
#include<QKeyEvent>
#include<QWheelEvent>
#include<QTimer>
#include<QLCDNumber>

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = 0);
    ~Widget();
public slots:
    void shownum(int num);

private:
    myclock *clock;
    QSlider *sd;
    int click;
    QLCDNumber *lcd;

protected:
    void mousePressEvent(QMouseEvent *event);
    void wheelEvent(QWheelEvent *event);
    void keyPressEvent(QKeyEvent *event);

};

#endif // WIDGET_H

/******************myclock.cpp********************/ 

#include "myclock.h"
#include<QWidget>
#include<QPaintEvent>
#include<QPainter>
#include<QString>
#include<QDebug>
#include<QBrush>

myclock::myclock(QWidget *parent) : QWidget(parent)
{
    //update();
    s = 0;
    time = new QTimer;
    time->start(1000);
    connect(time,SIGNAL(timeout()),SLOT(paint()));
}

void myclock::setvalue(int i)
{
    s = i;
    update();
}

void myclock::paintEvent(QPaintEvent *event)
{
    setFixedSize(600,600);
    QPainter pp(this);
    QBrush b(QColor(Qt::yellow));
    QPen p(QColor(Qt::black));
    p.setWidth(4);
    pp.setPen(p);
    pp.translate(this->width()/2,this->height()/2);
    pp.drawEllipse(QPoint(0,0),200,200);

    QPainter pp1(this);
    QPen p1(QColor(Qt::black));
    p1.setWidth(4);
    pp1.setPen(p1);
    pp1.translate(this->width()/2,this->height()/2);
    for(int i = 0;i < 12 ;i++)
    {
        pp1.drawLine(0,-190,0,-200);
        pp1.drawText(0,-170,QString::number(i));
        pp1.rotate(30);
    }

    QPainter pp2(this);
    QPen p2(QColor(Qt::black));
    p2.setWidth(2);
    pp2.setPen(p2);
    pp2.translate(this->width()/2,this->height()/2);
    for(int j = 0;j < 60 ;j++)
    {
        pp2.drawLine(0,-193,0,-200);
        pp2.rotate(6);
    }

    QPainter pp5(this);
    QPen p5(QColor(Qt::green));
    p5.setWidth(6);
    pp5.setPen(p5);
    pp5.translate(this->width()/2,this->height()/2);
    pp5.rotate(s*0.25/60);
    pp5.drawLine(0,0,0,-70);

    QPainter pp4(this);
    QPen p4(QColor(Qt::blue));
    p4.setWidth(5);
    pp4.setPen(p4);
    pp4.translate(this->width()/2,this->height()/2);
    pp4.rotate(s*0.5);
    pp4.drawLine(0,0,0,-120);

    QPainter pp3(this);//定义一个画家
    QPen p3(QColor(Qt::red));//画笔，颜色红
    p3.setWidth(4);//粗细10
    pp3.setPen(p3);//画家拿到笔
    pp3.translate(this->width()/2,this->height()/2);
    pp3.rotate(s*6);
    pp3.drawLine(0,0,0,-170);
    s++;
    qDebug()<<"s ="<<s;

}



/************widget.cpp************************************************/ 

#include "widget.h"
#include <QVBoxLayout>
#include<QDebug>
int now = 0;

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    click = 0;

    lcd = new QLCDNumber;
    lcd->setMinimumHeight(45);

    sd = new QSlider(this);
    sd->setOrientation(Qt::Horizontal);
    sd->setRange(0,864399);

    clock = new myclock(this);
    clock->setFixedSize(300,300);
    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(clock);
    vbox->addWidget(lcd);
    vbox->addWidget(sd);
    setLayout(vbox);

    connect(sd,SIGNAL(valueChanged(int)),clock,SLOT(setvalue(int)));
    connect(sd,SIGNAL(valueChanged(int)),this,SLOT(shownum(int)));

}

void Widget::shownum(int num)
{
    now = num;
    lcd->display(num);
}

void Widget::mousePressEvent(QMouseEvent *event)
{
    if( Qt::LeftButton == event->button())
    {
        click++;
        int c = click + now;
        sd->setValue(c);
        if(c == 864399)
        {
            click = 0;
            sd->setValue(1*click);
        }
    }
    else if( Qt::RightButton == event->button())
    {
        click--;
        sd->setValue(1*click);
        if(click == 0)
        {
            click = 359;
            sd->setValue(1*click);
        }
    }

}

void Widget::wheelEvent(QWheelEvent *event)
{
    if( Qt::WA_TranslucentBackground == event->delta())
    {
        click++;
        sd->setValue(1*click);
        if(click == 359)
        {
            click = 0;
            sd->setValue(1*click);
        }
    }
    else if( -120 == event->delta())
    {
        click--;
        sd->setValue(1*click);
        if(click == 0)
        {
            click = 359;
            sd->setValue(1*click);
        }
    }

}

void Widget::keyPressEvent(QKeyEvent *event)
{

    if( (Qt::Key_Up == event->key()) || (Qt::Key_Right == event->key()))
    {
        click++;
        sd->setValue(1*click);
        if(click == 359)
        {
            click = 0;
            sd->setValue(1*click);
        }
    }
    else if( (Qt::Key_Down == event->key()) || (Qt::Key_Left == event->key()))
    {
        click--;
        sd->setValue(1*click);
        if(click == 0)
        {
            click = 359;
            sd->setValue(1*click);
        }
    }

}


Widget::~Widget()
{

}





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