/// <summary>
 /// 创建实例
 /// </summary>
 /// <param name="operate"></param>
 /// <returns></returns>
 public static LineAnnotation Instance(Operate operate)
 {
     if (instance == null)
     {
         lock (lockObjcet) {
             if (instance == null)
             {
                 instance = new LineAnnotation(operate);
             }
         }
     }
     return(instance);
 }
 /// <summary>
 /// 构造
 /// </summary>
 /// <param name="operate"></param>
 private LineAnnotation(Operate operate)
 {
     this.pOperate = operate;
     ThreadPool.QueueUserWorkItem(new WaitCallback(Work));
 }