/// <summary>
 /// 构造函数。
 /// </summary>
 /// <param name="id">标注的ID。</param>
 /// <param name="point2D">坐标点。</param>
 /// <param name="bitmap">标识的自定义图片</param>
 /// <param name="toolTip">标注的提示。</param>
 public Marker(string id, Point2D point2D, Bitmap bitmap, ToolTip toolTip)
 {
     this._id = id;
     this._point2D = point2D;
     this._bitmap = bitmap;
     this._toolTip = toolTip;
     this._type = GeometryType.POINT;
 }
 /// <summary>
 /// 构造函数。
 /// </summary>
 /// <param name="id">标注的ID。</param>
 /// <param name="point2D">坐标点。</param>
 /// <param name="markerType">标注的类型。</param>
 /// <param name="toolTip">标注的提示。</param>
 public Marker(string id, Point2D point2D, MarkerType markerType, ToolTip toolTip)
 {
     this._id = id;
     this._point2D = point2D;
     this._markerType = markerType;
     this._toolTip = toolTip;
     this._type = GeometryType.POINT ;
 }