IFeatureSelection与IMap中选择要素的区别

IFeatureSelection接口由FeatureLayer类实现，主要用来存放用户在该图层中选择的要素，例如一般的属性查图，找到的元素一般放置在IFeatureSelection接口中。具体方法如下：

Members

	All Properties Methods	Description
	Add	Adds a feature to the selection set.
	BufferDistance	Buffer distance used for the selection.
	Clear	Clears the selection.
	CombinationMethod	Combination method for the selection.
	SelectFeatures	Selects features based upon the specifed criteria and combination method.
	SelectionChanged	Fires the features layer update event. Required when SelectionSet changes.
	SelectionColor	Selection color. (used when SetSelectionSymbol = FALSE).
	SelectionSet	The selected set of features.
	SelectionSymbol	Selection symbol.
	SetSelectionSymbol	Indicates if the selected set of features is drawn using the SelectionSymbol.

使用方法：

IFeatureSelection pfeaturesel = pfeatureLyr as IFeatureSelection;
pfeaturesel.Add(pFeature);//tianjia yuansu 
IFeatureSelection pfeaturesel = pfeatureLyr as IFeatureSelection;
pfeaturesel.Clear();

注意：操作完成后要更新MapControl
IMap接口中有 SelectFeature方法，用来向FeatureLayer的Selection中添加Feature

[C#]public void SelectFeature (
    ILayerLayer,
    IFeatureFeature);
ClearFeature用来清除整个Map地图文档中所有图层的Selection中的feature .

[C#]public void ClearSelection ();