本文主要为了实现QCustomPlot的鼠标键盘事件
首先你需要已经下载到QcustomPlot所需的文件，这里不多做介绍，网上很多。
qchart也有一个版本。需要请转到https://blog.csdn.net/amxld/article/details/112987703
主要任务
1：鼠标左键拖动
2：鼠标右键框选能够显示框选的部分
3：滚轮能够放大缩小图像
4：鼠标单击右键可以显示菜单 功能：清空，复位
5：图像上发显示当前坐标并且保留两位小数
6：在图像正上方加入曲线的标签（默认是在图像右上角，操作比较麻烦需要自己调节位置）
下面是效果图
下面直接进入代码吧！
头文件函数定义：
class MyCustomplot : public QCustomPlot
{
Q_OBJECT
public:
explicit MyCustomplot(QWidget *parent = 0);
~MyCustomplot();
void setZoomMode(bool mode);
public slots:
void setPlotData(const QVector<float> plots,QString lineName);
protected:
void mousePressEvent(QMouseEvent * event);
void mouseMoveEvent(QMouseEvent * event);
void mouseReleaseEvent(QMouseEvent * event);
protected slots:
void OnResetAction();
void OnClearAction();
private:
int m_graphIndex;
bool mZoomMode;
bool m_isMove;
QRubberBand * mRubberBand;
double m_minX,m_maxX,m_minY,m_maxY;
QCPRange m_Xaxis,m_Yaxis;
QPoint mOrigin;
QLabel *m_lbxy;
};
具体实现：
#include "mycustomplot.h"
#include "ui_mycustomplot.h"
#include <QMenu>
#include <QAction>
MyCustomplot::MyCustomplot(QWidget *parent) :
QCustomPlot(parent),
mZoomMode(true),
mRubberBand(new QRubberBand(QRubberBand::Rectangle, this))
{
mRubberBand->setBackgroundRole(QPalette::Light);
mRubberBand->setAutoFillBackground(true);
setInteractions(QCP::iRangeDrag |QCP::iRangeZoom);
plotLayout()->insertRow(0);
// plotLayout()->insertRow(1);
// plotLayout()->insertColumn(0);
m_lbxy = new QLabel(this);
QString LabelText = "X : "+QString::number(0,'f',2)+
" Y : "+QString::number(0,'f',2);
m_lbxy->setText(LabelText);
m_lbxy->setGeometry(20,40,250,15); //标签显示
// QCPTextElement *title = new QCPTextElement(this, "", QFont("sans", 12, QFont::Bold));
// plotLayout()->addElement(0, 0, title);
setInteraction(QCP::iRangeDrag,true);//使能拖动
xAxis->setRange(0,4096);
yAxis->setRange(0,100);
m_Xaxis = xAxis->range();
m_graphIndex = 0;
m_Yaxis = yAxis->range();
QCPAxisRect * axrect =new QCPAxisRect(this,false);
axrect->setAutoMargins(QCP::msNone);
axrect->insetLayout()->addElement(legend,Qt::AlignCenter); //设置标签显示格式
// QCPTextElement *title = new QCPTextElement(this, "", QFont("sans", 12, QFont::Bold));
// plotLayout()->addElement(0, 0, title);
setInteraction(QCP::iRangeDrag,true);//使能拖动
xAxis->setRange(0,4096);
yAxis->setRange(0,100);
m_Xaxis = xAxis->range();
m_graphIndex = 0;
m_Yaxis = yAxis->range();
QCPAxisRect * axrect =new QCPAxisRect(this,false);
axrect->setAutoMargins(QCP::msNone);
axrect->insetLayout()->addElement(legend,Qt::AlignCenter); //设置标签显示格式
}
MyCustomplot::~MyCustomplot()
{
}
void MyCustomplot::setZoomMode(bool mode)
{
mZoomMode = mode;
}
void MyCustomplot::setPlotData(const QVector<float> plots, QString lineName)
{
addGraph(); // blue line //加线
graph(m_graphIndex)->setPen(QPen(Qt::red));
//customPlot->graph(0)->setBrush(QBrush(QColor(240, 255, 200)));
graph(m_graphIndex)->setAntialiasedFill(false);
graph(m_graphIndex)->setName(lineName);
int count = 0;
for(auto it = plots.begin();it!=plots.end();it++)
{
graph(m_graphIndex)->addData(count, *it);
count++;
}
m_graphIndex++;
replot();
}
void MyCustomplot::mousePressEvent(QMouseEvent * event)
{
if (mZoomMode) //判断是否可以触发
{
if (event->button() == Qt::RightButton)
{
mOrigin = event->pos();
mRubberBand->setGeometry(QRect(mOrigin, QSize()));
mRubberBand->show();
}
}
QCustomPlot::mousePressEvent(event);
}
void MyCustomplot::mouseMoveEvent(QMouseEvent * event)
{
int x_pos = event->pos().x();
int y_pos = event->pos().y();
//鼠标坐标转化为CustomPlot内部坐标
float x_val = xAxis->pixelToCoord(x_pos);
float y_val = yAxis->pixelToCoord(y_pos);
QString LabelText = "X : "+QString::number(x_val,'f',2)+
" Y : "+QString::number(y_val,'f',2);
m_lbxy->setText(LabelText);
if (mRubberBand->isVisible())
{
mRubberBand->setGeometry(QRect(mOrigin, event->pos()).normalized());
}
QCustomPlot::mouseMoveEvent(event);\
}
void MyCustomplot::mouseReleaseEvent(QMouseEvent * event)
{
if (mRubberBand->isVisible())
{
const QRect zoomRect = mRubberBand->geometry();
int xp1, yp1, xp2, yp2;
if(zoomRect.width()>5&&zoomRect.height()>5)
{
//获取坐标
zoomRect.getCoords(&xp1, &yp1, &xp2, &yp2);
double x1 = xAxis->pixelToCoord(xp1);
double x2 = xAxis->pixelToCoord(xp2);
double y1 = yAxis->pixelToCoord(yp1);
double y2 = yAxis->pixelToCoord(yp2);
xAxis->setRange(x1, x2);
yAxis->setRange(y1, y2);
mRubberBand->hide();
replot();
}
else
{
QMenu *pMenu = new QMenu(this);
QAction *act_Clear = new QAction(tr("清空"), this);
QAction *act_Reset = new QAction(tr("复位"), this);
//把QAction对象添加到菜单上
pMenu->addAction(act_Clear);
pMenu->addAction(act_Reset);
//连接鼠标右键点击信号
connect(act_Clear, SIGNAL(triggered()), this, SLOT(OnClearAction()));
connect(act_Reset, SIGNAL(triggered()), this, SLOT(OnResetAction()));
//在鼠标右键点击的地方显示菜单
pMenu->exec(cursor().pos());
//释放内存
QList<QAction*> list = pMenu->actions();
foreach (QAction* pAction, list) delete pAction;
delete pMenu;
}
}
mRubberBand->hide();
QCustomPlot::mouseReleaseEvent(event);
}
//复位
void MyCustomplot::OnResetAction()
{
xAxis->setRange(m_Xaxis.lower,m_Xaxis.upper);
// xAxis->scaleRange(1.0,1.0);
// yAxis->scaleRange(1.0,1.0);
yAxis->setRange(m_Yaxis.lower,m_Yaxis.upper);
replot();
}
//清空
void MyCustomplot::OnClearAction()
{
m_graphIndex = 0;
this->clearGraphs();
replot();
}
代码就这些，可以试下有问题可以评论联系我。
QT4/5都可以使用，虽然没有Qchart方便好看，但是在QT4完美运行。
qchart也有一个版本。需要请转到https://blog.csdn.net/amxld/article/details/112987703