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Silverlight中同步調(diào)用WebClient的解決辦法，是同步！

更新時間：2011年04月07日 18:47:42 作者：

如何建立web服務(wù)并引用的細節(jié)，不是本文的介紹的目標，不再贅述。在silverlight調(diào)用服務(wù)器端服務(wù)的時候，默認情況下是進行異步調(diào)用的

代碼如下：

 
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; 
} 

若是你的調(diào)用非常復(fù)雜的話，比如當這個調(diào)用完成的時候開始下一個調(diào)用，然后又進行下一個調(diào)用，各個調(diào)用之間存在關(guān)聯(lián)關(guān)系的話，一直XX_DoWorkCompleted會讓你頭大，并且不利于代碼的管理。若碰到過這樣的問題的朋友一定很希望如果能夠同步調(diào)用就好了，這篇文章將幫到你?；蛘攥F(xiàn)在不需要，等你需要的時候記得用就行了，別像我當初那樣難為的不行。

主要是需要引用一個類庫的問題，這個類庫是外國人寫的，名稱為DanielVaughan.dll,下載完之后，首先需要在項目中添加對它的引用，如下圖，

然后在程序中添加對兩個空間的引用，如下圖：

將原來的添加botton1事件：

復(fù)制代碼代碼如下:

 
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同步調(diào)用--"+ res+"\r\n"; 
}); 
}); 
} 

這樣就可以實現(xiàn)對WebClient的同步調(diào)用了，當你需要關(guān)聯(lián)調(diào)用WebClient3次以上的時候可以考慮使用這個類庫，如果只是簡單的調(diào)用下的話，沒有必要使用。
頁面全部代碼：

復(fù)制代碼代碼如下:

 
<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="同步調(diào)用服務(wù)" 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="狀態(tài)：" 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="尚未調(diào)用服務(wù)" /> 
<Button Content="異步調(diào)用服務(wù)" 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="輸入文本：" /> 
</Grid> 
</UserControl> 

處理程序全部代碼：

復(fù)制代碼代碼如下:

 
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同步調(diào)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 += "異步調(diào)用--" + e.Result + "\r\n"; 
} 
} 
} 

Service代碼：

復(fù)制代碼代碼如下:

 
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) 
{ 
// 在此處添加操作實現(xiàn) 
return "調(diào)用服務(wù)完成，返回你輸入的值:"+aa; 
} 
// 在此處添加更多操作并使用 [OperationContract] 標記它們 
} 
} 