在QcustomPlot中，给横纵坐标添加箭头的方法
//在末尾添加箭头
customPlot->xAxis->setUpperEnding(QCPLineEnding::esSpikeArrow);
customPlot->yAxis->setUpperEnding(QCPLineEnding::esSpikeArrow);
怎么给图画虚线的方法
//设置虚线
QPen linesPen(Qt::red,1,Qt::DashLine);
line = new QCPItemStraightLine(customPlot);
line->setPen(linesPen);
line->setClipToAxisRect(true);
line->point1->setCoords(0,0);
line->point2->setCoords(0,0);
//虚线平行于x轴
line->point1->setCoords(customPlot->xAxis->range().lower,0.2);
line->point2->setCoords(customPlot->xAxis->range().upper,0.2);
文本框的设置
//创建文本对象
QCPItemText *text = new QCPItemText(customPlot);
//设置文本坐标解析方式
text->position->setType(QCPItemPosition::ptAxisRectRatio);
//设置位置在矩形区域的位置
text->setPositionAlignment(Qt::AlignLeft | Qt::AlignBottom);
//设置位置
text->position->setCoords(0.1,0.90);
//设置文本内容
text->setText("你好");
text->setTextAlignment(Qt::AlignLeft);
//设置颜色
text->setColor(QColor(Qt::red));
//设置页边距
text->setPadding(QMargins(1,1,1,1));
步长的设置
//创建对象
QSharedPointer<QCPAxisTickerFixed> intTicker( new QCPAxisTickerFixed );
//设置步长精度
intTicker->setTickStep(0.1);
//设置y轴步长
customPlot->yAxis->setTicker(intTicker);
设置坐标轴为矩形及坐标的刻度样式
ui->customPlot->xAxis2->setVisible(true);//x2轴可见
ui->customPlot->yAxis2->setVisible(true);//y2轴可见
ui->customPlot->xAxis2->setTicks(false);//x2刻度不可见
ui->customPlot->yAxis2->setTicks(false);//y2刻度不可见
ui->customPlot->yAxis->setSubTicks(false);//y1子刻度不可见
