http请求的get/post并不是难事，只是silverlight中一切皆是异步，所以代码看起来就显得有些冗长了，下面这个HttpHelper是在总结 园友 的基础上，修改得来：
1 namespace SLAwb.Helper 2 { 3 public sealed class MediaType 4 { 5 /// <summary> 6 /// "application/xml" 7 /// </summary> 8 public const string APPLICATION_XML = "application/xml"; 9 10 /// <summary> 11 /// application/json 12 /// </summary> 13 public const string APPLICATION_JSON = "application/json"; 14 15 /// <summary> 16 /// "application/x-www-form-urlencoded" 17 /// </summary> 18 public const string APPLICATION_FORM_URLENCODED = "application/x-www-form-urlencoded"; 19 20 } 21 }
1 using System; 2 using System.IO; 3 using System.Net; 4 using System.Threading; 5 6 namespace SLAwb.Helper 7 { 8 /// <summary> 9 /// Http工具类，用于向指定url发起Get或Post请求 10 /// http://yjmyzz.cnblogs.com/ 11 /// </summary> 12 public class HttpHelper 13 { 14 private string postData; 15 SynchronizationContext currentContext; 16 SendOrPostCallback sendOrPostCallback; 17 18 /// <summary> 19 /// 从指定url以Get方式获取数据 20 /// </summary> 21 /// <param name="url"></param> 22 /// <param name="completedHandler"></param> 23 public void Get(string url, DownloadStringCompletedEventHandler completedHandler) 24 { 25 WebClient client = new WebClient(); 26 client.DownloadStringCompleted += completedHandler; 27 client.DownloadStringAsync(new Uri(url)); 28 } 29 30 31 32 /// <summary> 33 /// 向指定url地址Post数据 34 /// </summary> 35 /// <param name="url"></param> 36 /// <param name="data"></param> 37 /// <param name="mediaType"></param> 38 /// <param name="synchronizationContext"></param> 39 /// <param name="callBack"></param> 40 public void Post(string url, string data, string mediaType, SynchronizationContext synchronizationContext, SendOrPostCallback callBack) 41 { 42 currentContext = synchronizationContext; 43 Uri endpoint = new Uri(url); 44 sendOrPostCallback = callBack; 45 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(endpoint); 46 request.Method = "POST"; 47 request.ContentType = mediaType; 48 postData = data; 49 request.BeginGetRequestStream(new AsyncCallback(RequestReadySocket), request); 50 } 51 52 private void RequestReadySocket(IAsyncResult asyncResult) 53 { 54 WebRequest request = asyncResult.AsyncState as WebRequest; 55 Stream requestStream = request.EndGetRequestStream(asyncResult); 56 57 using (StreamWriter writer = new StreamWriter(requestStream)) 58 { 59 writer.Write(postData); 60 writer.Flush(); 61 } 62 63 request.BeginGetResponse(new AsyncCallback(ResponseReadySocket), request); 64 } 65 66 private void ResponseReadySocket(IAsyncResult asyncResult) 67 { 68 try 69 { 70 WebRequest request = asyncResult.AsyncState as WebRequest; 71 WebResponse response = request.EndGetResponse(asyncResult); 72 using (Stream responseStream = response.GetResponseStream()) 73 { 74 StreamReader reader = new StreamReader(responseStream); 75 string paramStr = reader.ReadToEnd(); 76 currentContext.Post(sendOrPostCallback, paramStr); 77 } 78 } 79 catch (Exception e) 80 { 81 currentContext.Post(sendOrPostCallback, e.Message); 82 } 83 84 } 85 86 87 } 88 }
Silverlight中的测试代码：
xaml部分
1 <UserControl x:Class="SLAwb.MainPage" 2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 5 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 6 mc:Ignorable="d" 7 d:DesignHeight="480" d:DesignWidth="640"> 8 9 <Grid x:Name="LayoutRoot" Background="White"> 10 <Grid.RowDefinitions> 11 <RowDefinition Height="30"></RowDefinition> 12 <RowDefinition Height="*"></RowDefinition> 13 <RowDefinition Height="2*"></RowDefinition> 14 </Grid.RowDefinitions> 15 <Grid Grid.Row="0" Margin="3"> 16 <Grid.ColumnDefinitions> 17 <ColumnDefinition Width="40"></ColumnDefinition> 18 <ColumnDefinition Width="*"></ColumnDefinition> 19 <ColumnDefinition Width="75"></ColumnDefinition> 20 <ColumnDefinition Width="95"></ColumnDefinition> 21 <ColumnDefinition Width="80"></ColumnDefinition> 22 <ColumnDefinition Width="80"></ColumnDefinition> 23 </Grid.ColumnDefinitions> 24 <TextBlock VerticalAlignment="Center" TextAlignment="Right">地址：</TextBlock> 25 <TextBox Name="txtUrl" Grid.Column="1" Text="http://localhost/"></TextBox> 26 <TextBlock Grid.Column="2" VerticalAlignment="Center" TextAlignment="Right">MediaType：</TextBlock> 27 <TextBox Name="txtMediaType" Grid.Column="3" Text="application/xml"></TextBox> 28 <Button Name="btnPost" Content="Post" Grid.Column="4" Margin="3,1" Click="btnPost_Click"></Button> 29 <Button Name="btnGet" Content="Get" Grid.Column="5" Margin="3,1" Click="btnGet_Click"></Button> 30 </Grid> 31 32 <Grid Grid.Row="1"> 33 <Grid.ColumnDefinitions> 34 <ColumnDefinition Width="40"></ColumnDefinition> 35 <ColumnDefinition Width="*"></ColumnDefinition> 36 </Grid.ColumnDefinitions> 37 <TextBlock VerticalAlignment="Top" TextAlignment="Right">数据：</TextBlock> 38 <TextBox Name="txtPostData" Grid.Column="1" Margin="3" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"></TextBox> 39 </Grid> 40 41 <Grid Grid.Row="2"> 42 <Grid.ColumnDefinitions> 43 <ColumnDefinition Width="40"></ColumnDefinition> 44 <ColumnDefinition Width="*"></ColumnDefinition> 45 </Grid.ColumnDefinitions> 46 <TextBlock VerticalAlignment="Top" TextAlignment="Right">返回：</TextBlock> 47 <TextBox Name="txtResult" Grid.Column="1" Margin="3" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"></TextBox> 48 </Grid> 49 </Grid> 50 </UserControl>
cs部分
1 using SLAwb.Helper; 2 using System; 3 using System.Net; 4 using System.Threading; 5 using System.Windows; 6 using System.Windows.Controls; 7 8 namespace SLAwb 9 { 10 public partial class MainPage : UserControl 11 { 12 private SynchronizationContext currentContext; 13 14 15 public MainPage() 16 { 17 InitializeComponent(); 18 this.currentContext = SynchronizationContext.Current; 19 } 20 21 private void btnPost_Click(object sender, RoutedEventArgs e) 22 { 23 BeforeReturn(); 24 HttpHelper httpHelper = new HttpHelper(); 25 httpHelper.Post(txtUrl.Text, txtPostData.Text, txtMediaType.Text, currentContext, PostCompletedHandler); 26 } 27 28 private void PostCompletedHandler(Object obj) 29 { 30 txtResult.Text = obj.ToString(); 31 } 32 33 private void btnGet_Click(object sender, RoutedEventArgs e) 34 { 35 BeforeReturn(); 36 HttpHelper httpHelper = new HttpHelper(); 37 httpHelper.Get(txtUrl.Text, GetCompletedHandler); 38 } 39 40 41 void BeforeReturn() { 42 txtResult.Text = "loading..."; 43 } 44 45 46 void GetCompletedHandler(object sender, DownloadStringCompletedEventArgs e) 47 { 48 if (e.Error == null) 49 { 50 txtResult.Text = e.Result; 51 } 52 else 53 { 54 txtResult.Text = e.Error.Message; 55 } 56 } 57 } 58 }
