Silverlight中同步调用WebClient的解决办法，是同步！

private void button2_Click(object sender, RoutedEventArgs e) 
{ 
Service1Client sc = new Service1Client(); 
sc.DoWorkCompleted += new EventHandler<DoWorkCompletedEventArgs>(sc_DoWorkCompleted); 
sc.DoWorkAsync(textBox1.Text); 
} 
void sc_DoWorkCompleted(object sender, DoWorkCompletedEventArgs e) 
{ 
textBox2.Text = e.Result; 
} 
 

若是你的调用非常复杂的话，比如当这个调用完成的时候开始下一个调用，然后又进行下一个调用，各个调用之间存在关联关系的话，一直XX_DoWorkCompleted会让你头大，并且不利于代码的管理。若碰到过这样的问题的朋友一定很希望如果能够同步调用就好了，这篇文章将帮到你。或者现在不需要，等你需要的时候记得用就行了，别像我当初那样难为的不行。
主要是需要引用一个类库的问题，这个类库是外国人写的，名称为DanielVaughan.dll,下载完之后，首先需要在项目中添加对它的引用，如下图，

然后在程序中添加对两个空间的引用，如下图：



将原来的添加botton1事件：
 代码如下:

private void button1_Click(object sender, RoutedEventArgs e) 
{ 
string dd = textBox1.Text; 
string res = "NULL"; 
ThreadPool.QueueUserWorkItem(delegate 
{ 
Service1 sv = ChannelManager.Instance.GetChannel<Service1>(); 
/* Perform synchronous WCF call. */ 
res = SynchronousChannelBroker.PerformAction<string, string>(sv.BeginDoWork, sv.EndDoWork, dd); 
Dispatcher.BeginInvoke(delegate 
{ 
textBox2.Text +="\r\n同步调用--"+ res+"\r\n"; 
}); 
}); 
} 
 
这样就可以实现对WebClient的同步调用了，当你需要关联调用WebClient3次以上的时候 可以考虑使用这个类库，如果只是简单的调用下的话，没有必要使用。 
页面全部代码： 
 代码如下:

<UserControl x:Class="SilverlightApplication2.MainPage" 
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
mc:Ignorable="d" 
d:DesignHeight="300" d:DesignWidth="400" xmlns:dataInput="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.Input" Width="640" Height="480"> 
<Grid x:Name="LayoutRoot"> 
<Grid.Background> 
<LinearGradientBrush EndPoint="0.443,0.621" StartPoint="0.443,-2.509"> 
<GradientStop Color="#FF5C6768"/> 
<GradientStop Color="White" Offset="1"/> 
</LinearGradientBrush> 
</Grid.Background> 
<Button Content="同步调用服务" Height="40" HorizontalAlignment="Left" Margin="67,98,0,0" Name="button1" VerticalAlignment="Top" Width="120" Click="button1_Click" /> 
<dataInput:Label Height="50" HorizontalAlignment="Left" Margin="67,188,0,0" Name="label2" VerticalAlignment="Top" Width="46" Content="状态：" FontSize="16" /> 
<TextBox Height="40" HorizontalAlignment="Left" Margin="165,27,0,0" Name="textBox1" VerticalAlignment="Top" Width="300" FontSize="16" /> 
<TextBox Height="100" HorizontalAlignment="Left" Margin="146,188,0,0" Name="textBox2" VerticalAlignment="Top" Width="400" FontSize="16" TextWrapping="Wrap" Text="尚未调用服务" /> 
<Button Content="异步调用服务" Height="40" HorizontalAlignment="Left" Margin="346,98,0,0" Name="button2" VerticalAlignment="Top" Width="120" Click="button2_Click" /> 
<dataInput:Label Height="40" HorizontalAlignment="Left" Margin="67,27,0,0" Name="label1" VerticalAlignment="Top" Width="92" FontSize="16" Content="输入文本：" /> 
</Grid> 
</UserControl> 
 
处理程序全部代码： 
 代码如下:

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
using SilverlightApplication2.ServiceReference1; 
using System.Threading; 
using DanielVaughan; 
namespace SilverlightApplication2 
{ 
public partial class MainPage : UserControl 
{ 
public MainPage() 
{ 
InitializeComponent(); 
UISynchronizationContext.Instance.Initialize(Dispatcher); 
} 
private void button1_Click(object sender, RoutedEventArgs e) 
{ 
string dd = textBox1.Text; 
string res = "NULL"; 
ThreadPool.QueueUserWorkItem(delegate 
{ 
Service1 sv = ChannelManager.Instance.GetChannel<Service1>(); 
/* Perform synchronous WCF call. */ 
res = SynchronousChannelBroker.PerformAction<string, string>(sv.BeginDoWork, sv.EndDoWork, dd); 
Dispatcher.BeginInvoke(delegate 
{ 
textBox2.Text +="\r\n同步调用--"+ res+"\r\n"; 
}); 
}); 
} 
private void button2_Click(object sender, RoutedEventArgs e) 
{ 
Service1Client sc = new Service1Client(); 
sc.DoWorkCompleted += new EventHandler<DoWorkCompletedEventArgs>(sc_DoWorkCompleted); 
sc.DoWorkAsync(textBox1.Text); 
} 
void sc_DoWorkCompleted(object sender, DoWorkCompletedEventArgs e) 
{ 
textBox2.Text += "异步调用--" + e.Result + "\r\n"; 
} 
} 
} 
 
Service代码： 
 代码如下:

using System; 
using System.Linq; 
using System.Runtime.Serialization; 
using System.ServiceModel; 
using System.ServiceModel.Activation; 
namespace SilverlightApplication2.Web 
{ 
[ServiceContract(Namespace = "")] 
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] 
public class Service1 
{ 
[OperationContract] 
public string DoWork(string aa) 
{ 
// 在此处添加操作实现 
return "调用服务完成，返回你输入的值:"+aa; 
} 
// 在此处添加更多操作并使用 [OperationContract] 标记它们 
} 
} 
 

程序运行截图：
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3.




欢迎大家共同探讨，觉得好的话请推荐下。本人技术水平有限，如有不足之处，还请园友多多批评指正，谢谢。