How to: 使用http接收和发送简单的xml请求

核心提示： 异步调用Web服务在按钮的单击事件中构造URI.string symbol = _textBox.GetAttribute("value");// The target web service must be on the same server as this Sil

异步调用Web服务

在按钮的单击事件中构造URI.

string symbol = _textBox.GetAttribute("value");
// The target web service must be on the same server as this Silverlight application.
string serverUri = HtmlPage.DocumentUri.ToString();
int thisApp = serverUri.IndexOf("/Silverlight.net");
// Create the web service Url with this server as its base.
serverUri = serverUri.Substring(0, thisApp) + "/Silverlight.net.webservice/cs/WebService.asmx";
// Pass the input string to the EchoInput method in the web service.
System.Uri webServiceUri = new System.Uri(serverUri + "/EchoInput?input=" + symbol);

调用Web服务.

status.Text = String.Format("Calling {0}rn", webServiceUri.ToString());
_request = new BrowserHttpWebRequest(webServiceUri);
// Include the request object as the IAsyncResult.AsyncState property.
IAsyncResult iar = _request.BeginGetResponse(new AsyncCallback(OnResponseDownload),
　　　　　　　　　　_request);

处理响应.

public void OnResponseDownload(IAsyncResult iar)
{
　 string parsedtext = string.Empty;
　 try
　 {
　　　// Use the request object from the IAsyncResult.AsyncState property to obtain the response.
　　　HttpWebResponse response =　　　　　　　　　　((HttpWebRequest)iar.AsyncState).EndGetResponse(iar);
　　　if (response.StatusCode != HttpStatusCode.OK)
　　　　 throw new ApplicationException("HttpStatusCode " +
　　　　　 response.StatusCode.ToString() + " was returned.");
　　　// Read response
　　　StreamReader responseReader = new StreamReader(response.GetResponseStream());
　　　string rawResponse = responseReader.ReadToEnd();
　　　response.Close();
　　　XmlReader xr = XmlReader.Create(new StringReader(rawResponse));
　　　// Get main element
　　　xr.ReadToFollowing("string");
　　　// Get following text node
　　　xr.Read();
　　　_result.Text = "XmlReader parsed "" + xr.Value + """;
　　　xr.Close();
　　　responseReader.Close();
　 }
　 catch (Exception ex)
　 {
　　　 _status.Text = ex.Message;
　 }
}