我猜应该就是点太多导致的
你看看setCurveAttribute(QwtPlotCurve::Fitted,true);第一个参数的说明
/*!
Only in combination with QwtPlotCurve::Lines
A QwtCurveFitter tries to
interpolate/smooth the curve, before it is painted.
\note Curve fitting requires temorary memory
for calculating coefficients and additional points.
If painting in QwtPlotCurve::Fitted mode is slow it might be better
to fit the points, before they are passed to QwtPlotCurve.
*/
我刚才试,点多了以后也有问题。