如何调用ITopologicalOperator.Union方法成功地merge polygon 收藏

为什么题目要加个“成功地”，因为ITopologicalOperator的方法是bug非常多的，在90%的情况下能够按照你预想的工作，但是在10%的情况下，既不报错也不工作。这个merge的操作，成功地折磨了我两天。终于找到了解决的方法。

ICursor pCursor;

featureSelect.SelectionSet.Search(null, false, out pCursor);

IFeatureCursor pFeatureCursor = pCursor as IFeatureCursor;

IFeature pFeatureFirst = pFeatureCursor.NextFeature();

// 开始一个编辑操作，以能够撤销

m_EditWorkspace.StartEditOperation();

IGeometry pGeometryFirst = pFeatureFirst.Shape;

ITopologicalOperator2 topo_oper = (ITopologicalOperator2)pGeometryFirst;

//ITopologicalOperator的操作是bug很多的，先强制的检查下面三个步骤，再进行操作

//成功的可能性大一些

topo_oper.IsKnownSimple_2 = false;

topo_oper.Simplify();

pGeometryFirst.SnapToSpatialReference();

//这是准备合并的图斑使用的

ITopologicalOperator2 topo_oper2;

IGeometry pGeometryNext;

IFeature pFeatureNext = pFeatureCursor.NextFeature();

while (pFeatureNext != null)

{

pGeometryNext = pFeatureNext.ShapeCopy;

//与上面的同理

topo_oper2 = pGeometryNext as ITopologicalOperator2;

topo_oper2.IsKnownSimple_2 = false;

topo_oper2.Simplify();

pGeometryNext.SnapToSpatialReference();

//这才是合并图斑的关键

pGeometryFirst = topo_oper.Union(pGeometryNext);

pFeatureNext.Delete();

pFeatureNext = pFeatureCursor.NextFeature();

}

topo_oper.IsKnownSimple_2 = false;

topo_oper.Simplify();

pFeatureFirst.Shape = pGeometryFirst;

pFeatureFirst.Store();

m_EditWorkspace.StopEditOperation();