arcengine怎么获取igeometry的长度

//获取绘制的多边形
IGeometry drawGeo = _mapControl.TrackPolygon();
//判断绘制多边形是否为null，并不为空图形
if (drawGeo != null  !drawGeo.IsEmpty)
{
//图形转为点集
IPointCollection pPointColl = drawGeo as IPointCollection;
//遍历点集
for (int i = 0; i < pPointColl.PointCount; i++)
{
//获取点
IPoint pPoint = pPointColl.get_Point(i);
//输出点坐标
Console.WriteLine("x:" + pPoint.X.ToString("f2") + ", y:" + pPoint.Y.ToString("f2"));
}
}