通过线构造面（C# + ArcGIS Engine 9.2）

生成面之前的截图：


生成为面之后的截图：


从线生成面的方法代码：

/// <summary>
/// 通过线创建面
/// </summary>
/// <param name="pPolyline">线</param>
/// <returns>面</returns>
IPolygon ConstructPolygonFromPolyline(IPolyline pPolyline)
{
    IGeometryCollection pPolygonGeoCol = new PolygonClass();

    if ((pPolyline != null) && (!pPolyline.IsEmpty))
    {
        IGeometryCollection pPolylineGeoCol = pPolyline as IGeometryCollection;
        ISegmentCollection pSegCol = new RingClass();
        ISegment pSegment = null;
        object missing = Type.Missing;

        for (int i = 0; i < pPolylineGeoCol.GeometryCount; i++)
        {
            ISegmentCollection pPolylineSegCol = pPolylineGeoCol.get_Geometry(i) as ISegmentCollection;
            for (int j = 0; j < pPolylineSegCol.SegmentCount; j++)
            {
                pSegment = pPolylineSegCol.get_Segment(j);
                pSegCol.AddSegment(pSegment, ref missing, ref missing);
            }
            pPolygonGeoCol.AddGeometry(pSegCol as IGeometry, ref missing, ref missing);
        }
    }
    return pPolygonGeoCol as IPolygon;
}

调用示例：

ILayer pLayer = axMapControl1.get_Layer(1);
IFeatureLayer pFeatureLayer = pLayer as IFeatureLayer;
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
if (pFeatureClass.ShapeType == esriGeometryType.esriGeometryPolyline)
{
    IFeatureCursor pFeatureCursor = pFeatureClass.Search(null, false);
    IFeature pFeature = pFeatureCursor.NextFeature();

    ILayer pTargetLayer = axMapControl1.get_Layer(2);
    IFeatureLayer pTargetFeatureLayer = pTargetLayer as IFeatureLayer;
    IFeatureClass pTargetFeatureClass = pTargetFeatureLayer.FeatureClass;
    if (pTargetFeatureClass.ShapeType == esriGeometryType.esriGeometryPolygon)
    {
        IPolygon pPolygon = null;
        while (pFeature != null)
        {
            IPolyline pPolyline = pFeature.Shape as IPolyline;
            pPolygon = ConstructPolygonFromPolyline(pPolyline);
            if ((pPolygon != null) && (!pPolygon.IsEmpty))
            {
                if (!pPolygon.IsClosed)
                {
                    pPolygon.Close();
                }
                IFeature pNewFeature = pTargetFeatureClass.CreateFeature();
                pNewFeature.Shape = pPolygon;
                pNewFeature.Store();
                pFeature.Delete();
            }
            pFeature = pFeatureCursor.NextFeature();
        }
    }
}
axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);