internal Line(ZhouyiHexagram from, int index, Core.YinYang attribute, string text)
 {
     this.From      = from;
     this.LineIndex = index;
     this.YinYang   = attribute;
     this.LineText  = text;
 }
 /// <summary>
 /// 在纸上自下而上地绘制一条爻。
 /// Draw a line bottom to top on the paper.
 /// </summary>
 /// <param name="attribute">
 /// 爻的阴阳属性。
 /// The line's attribute.
 /// </param>
 /// <param name="isChanging">
 /// 指示是否为变爻。
 /// Whether the line is a changing line or not.
 /// </param>
 public void Draw(Core.YinYang attribute, bool isChanging)
 {
     lock (this.locker)
     {
         this.original.Add(attribute);
         this.changed.Add(isChanging ? !attribute : attribute);
     }
 }