Silverlight 中的WebClient 与 WebRequest 示例

ゝ一世哀愁。 2022-05-15 19:34 229阅读 0赞

## **WebClient**  ##

public partial class webclientSample : UserControl  
\{  
public webclientSample()  
\{  
InitializeComponent();  
//定义URL地址  
string url = "[http://localhost:2365/Sample.web/responseText.htm";][http_localhost_2365_Sample.web_responseText.htm]  
//创建WebClient对象  
WebClient webClient = new WebClient();  
//定义异步请求地址  
webClient.DownloadStringAsync(new Uri(url  
, UriKind.RelativeOrAbsolute));  
//定义请求完成的事件处理  
webClient.DownloadStringCompleted +=  
new DownloadStringCompletedEventHandler  
(webClient\_DownloadStringCompleted);  
\}

private void webClient\_DownloadStringCompleted(object sender  
, DownloadStringCompletedEventArgs e)  
\{  
//显示返回值  
MessageBox.Show(e.Result.ToString());  
\}  
\}

## **WebRequest**  ##

public partial class webrequestSample : UserControl  
\{  
//定义异步委托方法  
private delegate void DispatcherInvoke(string str);  
public webrequestSample()  
\{  
InitializeComponent();  
//定义URL地址  
string url = "[http://localhost:1398/Sample.web/responseText.htm";][http_localhost_1398_Sample.web_responseText.htm]  
//创建WebClient对象  
WebRequest request =  
HttpWebRequest.Create(new Uri(url  
, UriKind.RelativeOrAbsolute));  
//开始获取响应并进行异步回调  
request.BeginGetResponse(new AsyncCallback(responseReady)  
, request);  
\}  
private void responseReady(IAsyncResult ar)  
\{  
//返回异步回调结果对象  
WebRequest request = ar.AsyncState as WebRequest;  
//获取结果响应对象  
WebResponse response = request.EndGetResponse(ar);  
//定义返回流对象  
using (Stream stream = response.GetResponseStream())  
\{  
//使用流读取对象  
StreamReader reader = new StreamReader(stream);

//\*\*\* 直接读取将发生错误。  
//tbk.Text = "reader.ReadToEnd();

//使用Dispatcher异步执行委托方法  
tb.Dispatcher.BeginInvoke  
((DispatcherInvoke)processResult  
, reader.ReadToEnd());  
\}  
\}  
private void processResult(string result)  
\{  
//显示返回字符串  
tb.Text = result;  
\}  
\}

[http_localhost_2365_Sample.web_responseText.htm]: http://localhost:2365/Sample.web/responseText.htm%22;
[http_localhost_1398_Sample.web_responseText.htm]: http://localhost:1398/Sample.web/responseText.htm%22;