//删除与该站点关联的路线
 public bool deleteLink(MetroLink killLink)
 {
     try
         {
             _mLinks.Remove(killLink);
         }
         catch (System.Exception ex)
         {
             return false;
         }
         return true;
 }
 //添加与该站点关联的路线
 public bool addLink(MetroLink newLink)
 {
     try
         {
             _mLinks.Add(newLink);
         }
         catch (System.Exception ex)
         {
             return false;
         }
         return true;
 }