/// <summary>
/// 对要素类创建空间缓存
/// </summary>
/// <param name="featureClass"></param>
/// <returns></returns>
public static ISpatialCacheManager CreateCache(this IFeatureClass featureClass)
{
ISpatialCacheManager spatialCacheManager = (ISpatialCacheManager)((IDataset)featureClass).Workspace;//填充Spatial Cache
IEnvelope cacheExtent = ((IGeoDataset)featureClass).Extent;
if (!spatialCacheManager.CacheIsFull) //检测是否存在缓存
{
spatialCacheManager.FillCache(cacheExtent); //不存在，则创建缓存
}
return(spatialCacheManager);
}
private void iSpatialFilterSpatialCacheToolStripMenuItem_Click(object sender, EventArgs e)
{
Stopwatch myWatch = Stopwatch.StartNew();
//从MapControl中获取的点图层
IFeatureLayer pointFeatureLayer = axMapControl1.get_Layer(0) as IFeatureLayer;
IFeatureSelection pointFeatureSelection = pointFeatureLayer as IFeatureSelection;
//从MapControl中获取的面图层
IFeatureLayer polygonFeatureLayer = axMapControl1.get_Layer(1) as IFeatureLayer;
//填充Spatial Cache
ISpatialCacheManager spatialCacheManager = (ISpatialCacheManager)(pointFeatureLayer as IDataset).Workspace;
IEnvelope cacheExtent = (pointFeatureLayer as IGeoDataset).Extent;
//检测是否存在缓存
if (!spatialCacheManager.CacheIsFull)
{
//不存在，则创建缓存
spatialCacheManager.FillCache(cacheExtent);
}
//构建缓存后进行查询
IQueryFilter queryFilter = new QueryFilterClass();
//Search如果返回属性值的话设置SubFields会提高效率
queryFilter.SubFields = "Shape";
IFeatureCursor cursor = polygonFeatureLayer.Search(queryFilter, true);
IFeature polygonFeature = null;
while ((polygonFeature = cursor.NextFeature()) != null)
{
IGeometry queryGeometry = polygonFeature.Shape;
//构建空间查询
ISpatialFilter spatialFilter = new SpatialFilterClass();
spatialFilter.Geometry = queryGeometry;
spatialFilter.GeometryField = pointFeatureLayer.FeatureClass.ShapeFieldName;
spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelContains;
//选择的话可以不设置SubFields
pointFeatureSelection.SelectFeatures(spatialFilter as IQueryFilter, esriSelectionResultEnum.esriSelectionResultAdd, false);
}
int count = pointFeatureSelection.SelectionSet.Count;
//清空空间缓存
spatialCacheManager.EmptyCache();
axMapControl1.Refresh();
//释放游标
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(cursor);
myWatch.Stop();
string time = myWatch.Elapsed.TotalSeconds.ToString();
MessageBox.Show("The selected point count is " + count.ToString() + "! and " + time + " Seconds");
}
