自已根据Sar指示写的多空策略不能开平仓，求大神指教。感谢

Params Numeric AfStep( 0.02); Numeric AfLimit( 0.2 ) ; Numeric Lots(1); Vars Numeric oParCl( 0 ); Numeric oParOp( 0 ); Numeric oPosition( 0 ); Numeric oTransition( 0 ); Series<Numeric> ParCl(0); Events OnBar(ArrayRef<Integer> indexs) { Range[0:DataSourceSize() - 1] { ParabolicSAR( AfStep, AfLimit, oParCl, oParOp, oPosition, oTransition ) ; PlotAuto( \"ParCl\" , oParCl,0,Rgb(185,150,0),Enum_Dot) ; } //判断是否做多 //PlotNumeric(\"ParCl[1]\",ParCl[1]); //PlotNumeric(\"Close[1]\",Close[1]); //commentary(\"ParCl[1]:\"+Text(parcl[1])); //commentary(\"Close[1]:\"+Text(Close[1])); If(marKetposition <>1 And Close[1] > ParCl[1]) //marKetposition == 0 And { Buy(Lots,Open); } //判断是否做空 If(marKetposition <>-1 And Close[1] < ParCl[1]) //MarketPosition == 0 And { SellShort(Lots,Open); } }