大家来看看，ArcEngine开发，我这两个函数怎么老出错。
功能：在一个要素类中查找与直线pLine相交的要素

Public Function findCrossPointInFeatureClass(ByVal pFeatureLayer As IFeatureLayer, ByVal pLine As ILine) As Integer
Dim pGeo as IGeometry
pGeo=pLine

Dim pFilter As ISpatialFilter
Dim pFeatureSelection As IFeatureSelection

pFeatureSelection = pFeatureLayer

pFilter = New SpatialFilter '过滤算子
With pFilter
.Geometry = pGeo
.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects
End With

pFeatureSelection.SelectFeatures(pFilter, esriSelectionResultEnum.esriSelectionResultNew, False) '在这个地方出错
End Function

Public Function findCrossPointInFeatureClass(ByVal pFeatureClass As IFeatureClass, ByVal pLine As ILine) As Integer
Dim pGeo as IGeometry
pGeo=pLine

Dim pFilter As ISpatialFilter
pFilter = New SpatialFilter '过滤算子
With pFilter
.Geometry = pGeo
.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects
End With

pFeatureSelection.SelectFeatures(pFilter, esriSelectionResultEnum.esriSelectionResultNew, False)

Dim pFeatureCursor As IFeatureCursor
Dim count As Integer = 0
Dim pFeature As IFeature

pFeatureCursor = pFeatureClass.Search(pFilter, False) '在这个地方出错

End Function

[解决办法]
利用ISpatialFilter接口进行查询时，它的.Geometry必须是高级的Geometry，所以是不能传入ILine的，必须使用IPolyLine,所以你需要把传入的参数类型改为IPolyLine就可以了
[解决办法]
http://up2megis.spaces.live.com/blog/cns!7947820C29ABE0E8!150.entry

这里是我以前写过的一点东西，里面有你需要的部分