关于intersect方法

intersect方法的最后一个参数和该方法的检索容差有关嘛？为什么我用intersect方法查出来的polygon不是nothing，但面积却是负值？我设定的map.fullextent为该方法的最后一个参数

下面是你说的参数，在mo帮助里的说明，

extent: An object expression that evaluates to a Rectangle object.  This Rectangle should entirely contain the objects extent, and is used internally.

相交判断的结果应该是下面的，帮助上写的，*!*

The table below indicates what object type resultShape could be, depending on what shape types are used for object and intersectShape.


Point Points Line Polygon Rectangle Ellipse

Point Point Point Point Point Point Point
Points Point Point or Points Point or Points Point or Points Point or Points Point or Points
Line Point Point or Points Point or Points or Line Line Line Line
Polygon Point Point or Points Line Polygon Polygon or Rectangle Polygon
Rectangle Point Point or Points Line Polygon or Rectangle Rectangle Polygon or Rectangle
Ellipse Point Point or Points Line Polygon Polygon or Rectangle Polygon