Qt-chart 画折线图(以时间为x轴)

上图

代码

#include <iostream>
#include <random>
#include <qcategoryaxis.h>void MainWindow::testLine()
{//1、创建图表视图QChartView* view = new QChartView(this);//2.创建图表QChart* chart = new QChart();//3.将图表设置给图表视图view->setChart(chart);//设置标题chart->setTitle("");chart->legend()->show();//显示或者隐藏图例（默认显示）//4.构建x轴-日期时间轴QDateTimeAxis* axisX = new QDateTimeAxis(this);//设置轴的标题axisX->setTitleText("");//设置时间轴的范围,参数是两个时期时间QDateTimeaxisX->setRange(QDateTime(QDate(2000, 01, 01), QTime(0, 0, 0)),QDateTime(QDate(2000, 01, 10), QTime(0, 0, 0)));//设置刻度个数,刻度数算不好会会导致X轴看起来没有对中一样axisX->setTickCount(10);//设置刻度值的格式，和格式化时间字符串一样axisX->setFormat("MM.dd");axisX->setLabelsAngle(45);//添加轴chart->addAxis(axisX, Qt::AlignBottom);//5.构建y轴-数值轴QValueAxis* axisY = new QValueAxis(this);axisY->setRange(0, 100);axisY->setTickCount(11);axisY->setTitleText("Y");chart->addAxis(axisY, Qt::AlignLeft);//6.构建折线系列QLineSeries* line = new QLineSeries();//设置图例文本line->setName("tar");QLineSeries* line2 = new QLineSeries();//设置图例文本line2->setName("reality");for (int  i = 0; i < 7; i++){QString strDate = QString("%1.%2.%3").arg(2000).arg(1).arg(i + 1);{std::random_device rd;  // 用于获取随机数种子std::mt19937 gen(rd()); // 以 rd() 作为种子的 Mersenne Twister 引擎// 定义一个均匀分布的整数范围 [1, 100]std::uniform_int_distribution<> dis(1, 100);line->append(QDateTime(QDate::fromString(strDate, "yyyy.M.d"), QTime(0, 0, 0)).toMSecsSinceEpoch(), dis(gen));}{std::random_device rd;  // 用于获取随机数种子std::mt19937 gen(rd()); // 以 rd() 作为种子的 Mersenne Twister 引擎// 定义一个均匀分布的整数范围 [1, 100]std::uniform_int_distribution<> dis(1, 100);line2->append(QDateTime(QDate::fromString(strDate, "yyyy.M.d"), QTime(0, 0, 0)).toMSecsSinceEpoch(), dis(gen));}}//显示标签line->setPointLabelsVisible(true);line2->setPointLabelsVisible(true);//显示标签格式line->setPointLabelsFormat("(@yPoint)");line2->setPointLabelsFormat("(@yPoint)");//显示标签裁剪line->setPointLabelsClipping(false);line2->setPointLabelsClipping(false);chart->addSeries(line);chart->addSeries(line2);//7、将xy轴附加到折线line->attachAxis(axisX);line->attachAxis(axisY);line2->attachAxis(axisX);line2->attachAxis(axisY);setCentralWidget(view);
}