1
我有一个包含一些曲线的QwtPlot,我希望能够从这些曲线中获取选定的点(和曲线指针):通过单击并选择一个点通过拖动矩形选择点。QwtPlot如何选择点曲线
我使用下面的代码:
// Picker with click point machine to provide point selection
QwtPlotPicker* clickPicker = new QwtPlotPicker(this->canvas());
clickPicker->setStateMachine(new QwtPickerClickPointMachine);
clickPicker->setMousePattern(0,Qt::LeftButton,Qt::SHIFT);
connect(clickPicker, SIGNAL(appended(QPointF)),
this, SLOT(pointSelected(QPointF)));
// Picker with drag rect machine to provide multiple points selection
QwtPlotPicker* rectPicker = new QwtPlotPicker(
this->xBottom, this->yLeft, QwtPicker::RectRubberBand,
QwtPicker::AlwaysOff, this->canvas());
QwtPickerDragRectMachine* test = new QwtPickerDragRectMachine();
test->setState(QwtPickerMachine::RectSelection);
rectPicker->setStateMachine(test);
connect(rectPicker, SIGNAL(selected(QRectF)),
this, SLOT(pointsSelected(QRectF)));
但pointSelected槽被调用每一次我在QwtPlot点击,而不是只在一个曲线
BTW的时候,我也尝试将槽连接到信号QwtPlotPicker::selected(const QVector &pa)但它从未发射...