Silverlight同步通信

水深无声 2022-04-22 00:30 185阅读 0赞

SL调用WCF方法，默认是异步的，但有些情况，我们使用同步会来的方便些，下面的文章提供了一种方式。

[http://www.codeproject.com/KB/silverlight/SynchronousSilverlight.aspx][http_www.codeproject.com_KB_silverlight_SynchronousSilverlight.aspx]

上述提供的方式是基于服务端WCF服务接口实现，可是有时不需要WCF服务接口，下面对此进行补充：

WCF服务如下：

namespace DanielVaughan.Silverlight.Examples.Web
    {
        [ServiceContract(Namespace = "")]
    	[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    	public class SimpleService //: ISimpleService
    	{
    		//static int connectionCount;
    
            [OperationContract]
    		public string GetGreeting(string name)
    		{
    			Thread.Sleep(2000);
    			return "Hi " + name;
    		}
    
            [OperationContract]
            public List<string> GetDataList()
            {
                List<string> dataList = new List<string>();
                Random r = new Random(DateTime.Now.Millisecond);
                int max = r.Next(100);
                for (int i = 0; i <max ; i++)
                {
                    Thread.Sleep(100);
                    dataList.Add(i.ToString());
                }
                return dataList;
            }
    
            //public string InitiateConnection(string arbitraryIdentifier)
            //{
            //    return (++connectionCount).ToString();
            //}
    	}
    }

客户端：

private void btnGetDataSynch_Click(object sender, RoutedEventArgs e)
            {
                this.lbData.ItemsSource = null;
                ThreadPool.QueueUserWorkItem(delegate
                {
                    DisplayMessage("同步获取数据中...");
    
                    var ws = ChannelManager.Instance.GetChannel<SimpleService>();
                    try
                    {
                        ObservableCollection<string> dataList = SynchronousChannelBroker.PerformAction<ObservableCollection<string>>(ws.BeginGetDataList, ws.EndGetDataList);
                        
                        //if (Dispatcher.CheckAccess())
                        //{
                        //    this.lbData.ItemsSource = dataList;
                        //}
                        //else
                        //{
                        //    Dispatcher.BeginInvoke(delegate
                        //    {
                        //        this.lbData.ItemsSource = dataList;
                        //    });
                        //}
                        DisplayData(this.lbData, dataList);                
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.StackTrace);
                    }
    
                    DisplayMessage("同步获取数据完成");
                });
    
            }
    
            void DisplayMessage(string message)
            {
                DisplayText(this.tbMsg, message);
            }
    
            void DisplayText(TextBlock textBlock, string message)
            {
                if (Dispatcher.CheckAccess())
                {
                    textBlock.Text = message;
                }
                else
                {
                    Dispatcher.BeginInvoke(delegate
                    {
                        textBlock.Text = message;
                    });
                }
            }
    
            void DisplayData(ListBox listBox, ObservableCollection<string> dataList)
            {
                if (Dispatcher.CheckAccess())
                {
                    listBox.ItemsSource = dataList;
                }
                else
                {
                    Dispatcher.BeginInvoke(delegate
                    {
                        listBox.ItemsSource = dataList;
                    });
                }
            }

[http_www.codeproject.com_KB_silverlight_SynchronousSilverlight.aspx]: http://www.codeproject.com/KB/silverlight/SynchronousSilverlight.aspx