请教C#里怎么才能把临时图层设置在最上层

请问C#里如何才能把临时图层设置在最上层?
我想把图元放置在最前端

------解决方案--------------------
if (map != null)
{
if (map.Layers[MapCommonFactory.TempLayerAlias] != null)
{
map.Layers.Remove(MapCommonFactory.TempLayerAlias);
}
MapInfo.Engine.Session.Current.Catalog.CloseTable(MapCommonFactory.TempTableAlias);
MapInfo.Data.TableInfoMemTable ti = new MapInfo.Data.TableInfoMemTable(MapCommonFactory.TempTableAlias);
ti.Columns.Add(MapInfo.Data.ColumnFactory.CreateFeatureGeometryColumn(map.GetDisplayCoordSys()));
ti.Columns.Add(MapInfo.Data.ColumnFactory.CreateStyleColumn());
ti.Columns.Add(MapInfo.Data.ColumnFactory.CreateStringColumn( "ID ", 10));
ti.Columns.Add(MapInfo.Data.ColumnFactory.CreateStringColumn( "NAME ", 10));
MapInfo.Data.Table table = MapInfo.Engine.Session.Current.Catalog.CreateTable(ti);
map.Layers.Insert(0, new MapInfo.Mapping.FeatureLayer(table, "temlayer ", MapCommonFactory.TempLayerAlias));
}