效果图

开始

更新

include包

#include <QChartView>
#include <QtCharts/QChartView>

#include <QValueAxis>
#include <QDateTimeAxis>
#include <QSplineSeries>
#include <QDateTimeAxis>

QChart初始化

	mAxY = new QValueAxis();
	mAxDateX = new QDateTimeAxis();
	mSeries = new QLineSeries();

	mAxY->setRange(0, yMax);
	mAxY->setTickCount(6);	

	mAxDateX->setFormat("yyyy-M-d HH:mm s");// 145°时："yyyy-M-d HH:mm s\""
	mAxDateX->setLabelsAngle(60);
	mAxDateX->setTickCount(11);
	
	this->chart()->addSeries(mSeries);
	this->chart()->setTheme(QtCharts::QChart::ChartThemeBrownSand);
	this->chart()->setTitle("QDateTimeAxis_Demo");
	this->chart()->legend()->hide();
	this->chart()->addAxis(mAxY, Qt::AlignLeft);
	this->chart()->addAxis(mAxDateX, Qt::AlignBottom);
	
	mSeries->attachAxis(mAxY);// 此二句一定要放在 this->chart()->addAxis 语句之后，不然
	mSeries->attachAxis(mAxDateX);// 没有曲线显示
	

定时器刷新SLOT函数

void timeChart::updateSeries()
{
	static int cnt = 0;
	static QDateTime BeginTime, EndTime;

	if (FirstIn)
	{
		FirstIn = false;
		BeginTime = QDateTime::currentDateTime();
		EndTime = BeginTime.addMSecs(MaxSize*(TimerBreaks + 1));
		mAxDateX->setMin(BeginTime);
		mAxDateX->setMax(EndTime);
	}	

	qint64 x1 = QDateTime::currentMSecsSinceEpoch();
	
	qreal y = yMax / 2 + (yMax / 2.0)*sin(omiGa*cnt);
	cnt = cnt > (MaxSize - 1) ? 1 : (++cnt);

	if (mSeries->count() > (MaxSize-1))
	{
		mSeries->removePoints(0, 1);
		EndTime = QDateTime::currentDateTime();
		BeginTime = EndTime.addMSecs((qint64)MaxSize*(-1)*TimerBreaks);
	
		mAxDateX->setMin(BeginTime);
		mAxDateX->setMax(EndTime);
	}
	mSeries->append(x1, y);
	mSeries->show();
}

具体实现demo,可下载：https://download.csdn.net/download/birenxiaofeigg/11340358