重新实现QwtScaleDraw的label
class TimeScaleDraw: public QwtScaleDraw
{
public:
TimeScaleDraw( const QTime &base ):
baseTime( base )
{
}
virtual QwtText label( double v ) const
{
QTime upTime = baseTime.addSecs( static_cast<int>( v ) );
return upTime.toString();
}
private:
QTime baseTime;
};