Windows Phone 7开发遇到的事：使用get、post请求

蔷薇525

　　
　　当要向服务器发送get或post请求的时候，WP7一般会用到HttpWebRequst或WebClient这两种方法。
　　两者最大的区别：HttpWebRequst的回调是异步，WebClient的回调是同步。
　　我更喜欢用HttpWebRequst，下面是用法：
　　
　　GET
　　



string uri = "https://www.google.com/";
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(uri);
httpWebRequest.BeginGetResponse(ResponseCallback, httpWebRequest);


private void ResponseCallback(IAsyncResult result)
{
string response = null;
Stream stream = null;
try
{
//获取异步操作返回的的信息
HttpWebRequest httpWebRequest = (HttpWebRequest)result.AsyncState;
//结束对 Internet 资源的异步请求
WebResponse webResponse = httpWebRequest.EndGetResponse(result);
stream = webResponse.GetResponseStream();
using (StreamReader sr = new StreamReader(stream))
{
response = sr.ReadToEnd();
}      
}
catch { }
finally
{
if (stream != null)
{
stream.Close();
}
}
//这里不为空代表获得回复了
if (response != null)
{
//因为HttpWebRequest的回调是异步，不在UI线程上。所以要改变UI线程上的控件属性就要用Dispatcher.BeginInvoke()。
Dispatcher.BeginInvoke(() =>
{
textBlock.Text = response;
});
}
}
POST



string uri = "https://www.google.com/";
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(uri);
httpWebRequest.Method = "POST";
httpWebRequest.ContentType = "application/x-www-form-urlencoded";
httpWebRequest.BeginGetRequestStream(StreamCallback, httpWebRequest);

　　这里是先获得向服务器写入的一个流，比如要向服务器发送一个字符串“啦啦啦”（注意编码）：



private void StreamCallback(IAsyncResult result)
{
HttpWebRequest httpWebRequest = (HttpWebRequest)result.AsyncState;
using (Stream stream = httpWebRequest.EndGetRequestStream(result))
{
byte[] entryBytes = Encoding.UTF8.GetBytes("啦啦啦");
stream.Write(entryBytes, 0, entryBytes.Length);
}
//这里就和上面GET方法获得回复回调一样，用 private void ResponseCallback(IAsyncResult result) 这个方法。
    httpWebRequest.BeginGetResponse(ResponseCallback, httpWebRequest);
}