发票查验---异步处理多条记录---demo代码

       /// 窗体加载事件
        /// </summary>
        /// <param name="obj"></param>
        private void Loaded(object obj)
        {
            _selfView = obj as UserControl;
            if (_selfView == null)
            {
                LogHelper.WriteLog(this.GetType() + ".Loaded方法中，通过命令绑定传入的参数obj为null");
                MaskPanelHelper.ShowMessageBoxWithMask("查验失败，请重试！");
                return;
            }

         //模拟做了一个循环（没有实际意义，只是表明异步并发查验多条记录）

          for(i=0;i<10;i++)

           {
                 AsyncCheckSingleInvoice();

             }
        }

        Action _action = null;
        /// <summary>
        /// 异步查验单张发票
        /// </summary>
        private void AsyncCheckSingleInvoice()
        {
            //var action = new Action(CheckSingleInvoice);
            //action.BeginInvoke(CheckInvoicesCallback, null);

            _action = new Action(CheckSingleInvoice);
            _action.BeginInvoke(CheckInvoicesCallback, null);
        }

        /// <summary>
        /// 查验单票（异步委托方法）
        /// </summary>
        private Invoice CheckSingleInvoice()
        {
            //网络故障检测
            if (!NetWorkHelper.IsConnectedInternet())
            {
                Application.Current.Dispatcher.Invoke((Action)(() => { MaskPanelHelper.ShowMessageBoxWithMask("网络故障，请检查"); }));
                return;
            }

         .......

         return _singleInvoice;  //查验完毕，再返回这张发票信息

       }

 

       /// <summary>
        /// 查验单票完毕后的回调
        /// </summary>
        private void CheckInvoicesCallback(IAsyncResult ir)
        {
            //异步委托的结果
            AsyncResult ar = ir as AsyncResult;
            if (ar != null)
            {
                var action = (Action)ar.AsyncDelegate;//异步委托方法
                action.EndInvoke(ar);//获得 "被异步委托”的“CheckSingleInvoice”方法的返回值
            }

            ........
            }

        }

说明：当这个 “被异步委托” 的 “CheckSingleInvoice”执行完毕后，就会自动执行 “CheckInvoicesCallback” 回调方法，并且在CheckInvoicesCallback中可以获得CheckSingleInvoice方法的返回值