调用
IPointCollection pc=new PathClass();
IGeomeytryCollection gc=new PolylineClass();
IPoint p=new PointClass();
pc.AddPoint(p,ref missing,ref missing);
.....//加点
gc.AddGeometry(pc as IGeometry,ref missing,ref missing);
IGeometryCollection ggc=MakeMutiPoint(gc as IGeometry,100);
for(int i=0;j<ggc.GeometryCount)
{
var pp=ggc.Geometry[i] as IPoint;
}