QT QcustomPlot的使用（二）

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

 

获取鼠标所在位置的坐标

int x_pos = e->pos().x();
int y_pos = e->pos().y();
qDebug()<<"event->pos()"<<e->pos();

 

鼠标坐标转化为CustomPlot内部坐标

float x_val = ui->customPlot->xAxis->pixelToCoord(x_pos);
float y_val = ui->customPlot->yAxis->pixelToCoord(y_pos);
qDebug()<<x_val<<y_val;

 

 

获取曲线的个数

int count = ui->customPlot->graphCount();

 

获取曲线上的点个数

int count = ui->customPlot->graph(0)->dataCount();

 

获取曲线上所有的点的x和y

QVector<double> y_data[ui->customPlot->graph(0)->dataCount()], x_data[ui->customPlot->graph(0)->dataCount()];

for (int i = 0;i < ui->customPlot->graph(k)->dataCount();i++) {
      float x = ui->customPlot->graph(k)->data()->at(i)->key;
      float y = ui->customPlot->graph(k)->data()->at(i)->value;
      x_data.append(x);
      y_data.append(y);
}

 

QToolTip提示框

QToolTip::showText(mapToGlobal(e->pos()),QString(str),this);