Qwt中鼠标获取坐标点

 void getPoint(QwtPlot *plot)

 {

       QPoint point = plot->canvas()->mapFromGlobal(QCursor::pos());

       QString info.sprintf("x = %g, y = %g",

                      plot ->invTransFrom(Qwtplot::xBottom,point.x()),

                      plot ->invTransFrom(Qwtplot::yLeft,point.y()

                       );

 }                    

Qwt获取坐标