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;

}