使用Qt画出直方图和分位数图

来源：互联网发布：万网域名交易平台编辑：程序博客网时间：2024/05/19 13:08

来源：物联网智能信息处理课程的一个小作业

使用工具：Qt5.8

平台：Mac os 10.11

要求：

一些说明：

1.Qt的窗口绘制函数为

void paintEvent(QPaintEvent *event);

需要从父类继承，然后自己实现，我们的有关绘图的操作就在这里实现。

2.Qt的绘图函数我们使用到的绘图相关函数主要为QPainter，QColor等，QBrush等，用法比较初级。

3.本程序的重点在于在坐标的变换，在写程序之前，一定会要画好早图，只有明白了坐标的变换规则，才能顺利的完成自己的程序。

4.一般的窗口的坐标原点都是客户区左上角，向右为X轴正方向，向下为Y轴正方向。

结果展示：

工程的结构：

项目代码：

IIPDraw2.pro

#-------------------------------------------------## Project created by QtCreator 2017-05-14T14:54:02##-------------------------------------------------QT       += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsTARGET = IIPDraw2TEMPLATE = app# The following define makes your compiler emit warnings if you use# any feature of Qt which as been marked as deprecated (the exact warnings# depend on your compiler). Please consult the documentation of the# deprecated API in order to know how to port your code away from it.DEFINES += QT_DEPRECATED_WARNINGS# You can also make your code fail to compile if you use deprecated APIs.# In order to do so, uncomment the following line.# You can also select to disable deprecated APIs only up to a certain version of Qt.#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0SOURCES += main.cpp\        mainwindow.cppHEADERS  += mainwindow.hFORMS    += mainwindow.ui

mainwindow.h

#ifndef MAINWINDOW_H#define MAINWINDOW_H#include <QMainWindow>namespace Ui {class MainWindow;}class MainWindow : public QMainWindow{    Q_OBJECTpublic:    explicit MainWindow(QWidget *parent = 0);    ~MainWindow();    void calc();    void paintEvent(QPaintEvent *event);private:    Ui::MainWindow *ui;    int P1A[10]={0},P1B[10]={0};    QList<int> listA,listB;};#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"#include <QApplication>int main(int argc, char *argv[]){    QApplication a(argc, argv);    MainWindow w;    w.show();    return a.exec();}

main window.cpp

#include "mainwindow.h"#include "ui_mainwindow.h"#include <QPainter>MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    calc();}MainWindow::~MainWindow(){    delete ui;}void MainWindow::calc(){    listA<<19<<18<<18<<15<<18         <<11<<16<<19<<17<<17         <<20<<17<<19<<20<<20         <<15<<15<<16;    listB<<19<<15<<20<<20<<17         <<18<<18<<15<<16<<18         <<15<<19<<20<<19<<19         <<16<<17<<13<<15;    QListIterator<int> i(listA);    QListIterator<int> j(listB);    for(;i.hasNext();)    {        int num = i.next();        P1A[num-10-1]++;    }    for(;j.hasNext();)    {        int num = j.next();        P1B[num-10-1]++;    }}void MainWindow::paintEvent(QPaintEvent *event){    Q_UNUSED(event);    QPainter painter(this);    painter.setPen(QColor(0,0,0));    //绘制直方图 远点50，400，单位高度50 单位宽度20    painter.drawLine(50,400,360,400);     //x轴 单位长10，30个单位，总长350    painter.drawLine(50,400,50,100);      //y轴 单位50，5个单位，总长300    painter.drawLine(50,100,45,105);      //上箭头    painter.drawLine(50,100,55,105);      //上箭头    painter.drawLine(355,395,360,400);    //右箭头    painter.drawLine(355,405,360,400);    //右箭头    int xi = 10;            //单位长度x    int yi = 50;            //单位长度y    int u = 3;              //刻度的长度    //画y轴的刻度    for(int i=0;i<=5;i++)    {        painter.drawLine(50,400-yi*i,50+u,400-yi*i);        //画刻度线        painter.drawText(QPoint(40,403-yi*i),QString::number(i));   //画刻度数字    }    //画x轴的刻度    for(int i=11;i<=20;i++)    {        painter.drawLine(40+xi*3*(i-10),400,40+xi*3*(i-10),403);    //画刻度线        painter.drawText(QPoint(35+xi*3*(i-10),420),QString::number(i-10)); //画刻度数字    }    painter.setBrush(QColor(62,147,192));    for(int i=11;i<=20;i++)    {        painter.drawRect(60+(i-10-1)*30,400-50*P1A[i-10-1],10,50*P1A[i-10-1]);    }    painter.setBrush(QColor(62,102,149));    for(int i=11;i<=20;i++)    {        painter.drawRect(70+(i-10-1)*30,400-50*P1B[i-10-1],10,50*P1B[i-10-1]);    }    //绘制分位数图 远点500，400，单位高度50 单位宽度20    painter.drawLine(500,400,950,400);     //x轴 单位长100，4个单位，总长450    painter.drawLine(500,400,500,70);      //y轴 单位30，10个单位，总长330    painter.drawLine(500,70,495,75);      //上箭头    painter.drawLine(500,70,505,75);      //上箭头    painter.drawLine(945,395,950,400);    //右箭头    painter.drawLine(945,405,950,400);    //右箭头    int xj = 100;            //单位长度x    int yj = 30;            //单位长度y    int v = 3;              //刻度的长度    //画y轴的刻度    for(int i=11;i<=20;i++)    {        painter.drawLine(500,400-yj*(i-10),500+v,400-yj*(i-10));        //画刻度线        painter.drawText(QPoint(480,403-yj*(i-10)),QString::number(i));   //画刻度数字    }    //画x轴的刻度    for(int i=0;i<=4;i++)    {        painter.drawLine(500+xj*i,400,500+xj*i,397);    //画刻度线        painter.drawText(QPoint(490+xj*i,420),QString::number(i/4.0)); //画刻度数字    }    //画出分为图点的位置    //x的位置为：(float)num/listA.length()*400+500  y的位置为：400-(i+1)*30    int num=1;        //内层循环计数    painter.setBrush(QColor(62,147,192));    for(int i=0;i<10;i++)    {        for(int j=1;j<=P1A[i];j++)        {            painter.drawEllipse((float)num/listA.length()*400+500,400-(i+1)*30,8,8);            num++;        }    }    num = 1;    painter.setBrush(QColor(62,102,149));    for(int i=0;i<10;i++)    {        for(int j=1;j<=P1B[i];j++)        {            painter.drawEllipse((float)num/listB.length()*400+500,400-(i+1)*30,8,8);            num++;        }    }    //给出说明    painter.drawText(QPoint(360,520),"说明：");    painter.drawText(QPoint(450,520),"A班");    painter.drawText(QPoint(450,570),"B班");    painter.setBrush(QColor(62,147,192));    painter.drawRect(400,500,30,30);    painter.setBrush(QColor(62,102,149));    painter.drawRect(400,550,30,30);    //标题    QFont font;    font.setFamily("Microsoft YaHei");    font.setPointSize(50);    font.setItalic(true);    painter.setFont(font);    painter.drawText(rect(), Qt::AlignHCenter, "A班和B班的直方图和分位数图");}

mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?><ui version="4.0"> <class>MainWindow</class> <widget class="QMainWindow" name="MainWindow">  <property name="geometry">   <rect>    <x>0</x>    <y>0</y>    <width>1000</width>    <height>700</height>   </rect>  </property>  <property name="minimumSize">   <size>    <width>1000</width>    <height>700</height>   </size>  </property>  <property name="maximumSize">   <size>    <width>1000</width>    <height>700</height>   </size>  </property>  <property name="windowTitle">   <string>MainWindow</string>  </property>  <widget class="QWidget" name="centralWidget"/>  <widget class="QMenuBar" name="menuBar">   <property name="geometry">    <rect>     <x>0</x>     <y>0</y>     <width>1000</width>     <height>22</height>    </rect>   </property>  </widget>  <widget class="QStatusBar" name="statusBar"/> </widget> <layoutdefault spacing="6" margin="11"/> <resources/> <connections/></ui>

本程序只是QT图形绘制的最简单最基础的应用，如有哪些写的不好的地方，忘各位批评指正。

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