private void axMapControl1_OnMouseDown(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e)
{
IMap pMap;
IActiveView pActiveView;
pMap = axMapControl1.Map;
pActiveView = pMap as IActiveView;
//得到一个Envelope对象
IEnvelope pEnvelope;
pEnvelope = axMapControl1.TrackRectangle();
//新建选择集环境对象
ISelectionEnvironment pSelectionEnvironment;
pSelectionEnvironment = new SelectionEnvironmentClass();
if (e.button == 1) //鼠标左键拉框选中
{
//改变选择集的默认颜色
pSelectionEnvironment.DefaultColor = getRGB(255, 0, 0);
//选择要素，将它们放入选择集
pMap.SelectByShape(pEnvelope, pSelectionEnvironment, false);
pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
}
else if (e.button == 2) //鼠标右键取消操作
{
{
IMap pMap;
IActiveView pActiveView;
pMap = axMapControl1.Map;
pActiveView = pMap as IActiveView;
//得到一个Envelope对象
IEnvelope pEnvelope;
pEnvelope = axMapControl1.TrackRectangle();
//新建选择集环境对象
ISelectionEnvironment pSelectionEnvironment;
pSelectionEnvironment = new SelectionEnvironmentClass();
if (e.button == 1) //鼠标左键拉框选中
{
//改变选择集的默认颜色
pSelectionEnvironment.DefaultColor = getRGB(255, 0, 0);
//选择要素，将它们放入选择集
pMap.SelectByShape(pEnvelope, pSelectionEnvironment, false);
pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
}
else if (e.button == 2) //鼠标右键取消操作
{