利用IFeatureIndex2 和 IIndexQuery2提高空间查询效率

 

            StringBuilder tSB = new StringBuilder();

            IFeatureClass tFeatureClass = (IFeatureClass)this._InDataset;

           

            IGeoDataset tGeodataset=(IGeoDataset)this._InDataset;

 

            IFeatureIndex2 tFeatureIndex = new FeatureIndexClass();

            ESRI.ArcGIS.esriSystem.ITrackCancel tTrackCancel=new CancelTracker();

            IIndexQuery tIndexQuery = tFeatureIndex as IIndexQuery;

            IIndexQuery2 tIndexQuery2 = (IIndexQuery2)tIndexQuery;

            tFeatureIndex.FeatureClass = tFeatureClass;

            tFeatureIndex.set_OutputSpatialReference(tFeatureClass.OIDFieldName, tGeodataset.SpatialReference);

            tFeatureIndex.Index(tTrackCancel, tGeodataset.Extent);//tGeodataset.Extent

 

            int iDex = tFeatureClass.FindField(this._FieldName);

            for (int i = 0; i < _Rows; i++)

            {

                for (int j = 0; j < _Cols; j++)

                {

                    double[] pX = null;

                    double[] pY = null;

                    getPolygon(i, j, ref pX, ref pY);

                    IPoint tPoint = new PointClass();

                    tPoint.X = pX[0] + (pX[3] - pX[0]) / 2;

                    tPoint.Y = pY[0] + (pY[0] - pY[3]) / 2;

                    

                    int oid= tIndexQuery2.WithinFeature(tPoint);

                    if (oid>-1)

                    {

                        IFeature tFeature = tFeatureClass.GetFeature(oid);

                        object o = tFeature.get_Value(iDex);

                        if (o != null && o.ToString().Trim() != "")

                        {

                            tSB.Append(o.ToString() + "  ");

                        }

                        else

                        {

                            tSB.Append("-9999" + "  ");

                        }

                    }

                    else

                    {

                        tSB.Append("-9999" + "  ");

                    }

                   

                }

            }

         

            return tSB;

        }

 

 

利用IFeatureIndex2 和 IIndexQuery2来作空间检索，比用IFeatureCursor tFeatureCursor= tFeatureClass.Search(null, true);然后遍历IFeature快一些。