WP7下的Get Post都是异步的
关于RX
http://www.cnblogs.com/yangecnu/archive/2012/11/03/Introducting_ReactiveExtensions.html
我初步理解的Rx,是观察者模式的一种实现
Url很简单，先来看看URL
URL:
http://www.douban.com/j/app/loginMethod:
POST-
Arguments:
app_name:radio_desktop_winversion:100email:用户帐号password:明文密码
Header:
Content-Type: application/x-www-form-urlencodedResponse (
application/json)
在WP7下的Post过程大致如下（Get过程相对简单，只需要2步）:
第一步：
public void PostMethod(string Url,string Postdata)
{ HttpWebRequest request;
request = (HttpWebRequest)WebRequest.Create(new Uri(Url));
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.BeginGetRequestStream(new AsyncCallback(RequestCallback), request); _postdata = Postdata;
}
第二步：
private void RequestCallback(IAsyncResult asyncResult)
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
UTF8Encoding encoding = new UTF8Encoding();
Stream _body = request.EndGetRequestStream(asyncResult);
byte[] formBytes = encoding.GetBytes(_postdata);//这是通过post方式传的
_body.Write(formBytes, , formBytes.Length);
_body.Close();
request.BeginGetResponse(new AsyncCallback(ResponseCallback), request); }
第三步：
private void ResponseCallback(IAsyncResult asyncResult)
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState; WebResponse httpwebresponse = request.EndGetResponse(asyncResult);
Stream stream= httpwebresponse.GetResponseStream();
StreamReader reader = new StreamReader(stream);
string result=reader.ReadToEnd(); // Deployment.Current.Dispatcher.BeginInvoke(_postret, result); }
刚学习了Rx，想看看如果用Rx应该怎么做
先来回顾下Rx 如下
public interface IObservable<T> { IDisposable Subscribe(IObserver<T> observer); }
public interface IObserver<T>
{
void OnCompleted();
void OnError(Exception exception);
void OnNext(T value);
}
在我的System.Reactive.Linq的Observable静态类下，定义了了IObservable<T>的很多扩展方法，
public static IObservable<TResult> Select<TSource, TResult>(this IObservable<TSource> source, Func<TSource, TResult> selector)
public static IObservable<TResult> SelectMany<TSource, TResult>(this IObservable<TSource> source, Func<TSource, IEnumerable<TResult>> selector)
这些扩展方法反映了我们可以像Linq一样获得一个IObservable<T>
下面是获得一个IObservable<T>的最简单的方法
public static IObservable<TResult> Return<TResult>(TResult value)
用这个方法得到的IObservable<T>后就可以注册了，在我的System.Reactive.Core.dll，System命名空间下的ObservableExtensions静态类扩展了IObservable<T>的注册方式：
public static IDisposable Subscribe<T>(this IObservable<T> source, Action<T> onNext)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (onNext == null)
{
throw new ArgumentNullException("onNext");
}
return source.Subscribe(new AnonymousObserver<T>(onNext, Stubs.Throw, Stubs.Nop));
}
具体实现我们不具体去关注，但是我们知道在11行，是New了一个匿名的观察者Observer了。
接下来看看FromAsyncPattern
public static Func<IObservable<TResult>> FromAsyncPattern<TResult>(Func<AsyncCallback, object, IAsyncResult> begin, Func<IAsyncResult, TResult> end)
这是个静态方法，返回一个返回值类型为IObservable<TResult>,无实参,的委托
先回顾用Rx实现的一个Get方法：
public LoginTest()
{ var func= Observable.FromAsyncPattern<HttpWebRequest,HttpWebResponse>(Webrequest,WebResponse);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("http://www.baidu.com"); var observable= func(request);
observable.Subscribe(
(result) =>
{
var stream = result.GetResponseStream();
var sr = new StreamReader(stream);
var baiduhttphtml = sr.ReadToEnd();
}); } IAsyncResult Webrequest(HttpWebRequest request,AsyncCallback callbcak,object ob)
{
return request.BeginGetResponse(callbcak, request);
}
HttpWebResponse WebResponse(IAsyncResult result)
{
var request = result.AsyncState as HttpWebRequest;
return (HttpWebResponse)request.EndGetResponse(result);
}
这样的Get方式看起来很简洁
昨晚敲了一下,Post方式如下：（回去后在VS2013上用RX，发现他提示我最好用await，Task等新特性来做异步，今晚回去试试，实验室是VS2010）
class MyHttpRequest
{
string PostData;
AsyncCallback save;//用于中间传递
public IObservable<string> PostMethod(string URL, string PostData)
{
this.PostData = PostData;
var func = Observable.FromAsyncPattern<HttpWebRequest,string>(Webrequest, ResponseCallback);//直接返回string
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
return func(request); }
IAsyncResult Webrequest(HttpWebRequest request, AsyncCallback callbcak, object ob)
{
save = callbcak;//保存CallBack
return request.BeginGetRequestStream(act, request);
}
void act(IAsyncResult asyncResult)
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
UTF8Encoding encoding = new UTF8Encoding();
Stream _body = request.EndGetRequestStream(asyncResult);
byte[] formBytes = encoding.GetBytes(this.PostData);//这是通过post方式传的
_body.Write(formBytes, , formBytes.Length);
_body.Close();
request.BeginGetResponse(save, request);//用保存的CallBack }
string ResponseCallback(IAsyncResult asyncResult)
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
WebResponse httpwebresponse = request.EndGetResponse(asyncResult);
Stream stream = httpwebresponse.GetResponseStream();
StreamReader reader = new StreamReader(stream);
return reader.ReadToEnd();
}
}
好了，现在很清楚了，来试试效果
public LoginTest()
{
//发出一个消息 跟MVVMLight Messenger有点像
var observable= new MyHttpRequest().PostMethod("http://www.douban.com/j/app/login", "app_name=radio_desktop_win&version=100&email=327442095@qq.com&password="); //直接在这里订阅一个匿名接收者
observable.Subscribe((result) =>
{
Debug.WriteLine(result);
});
Debug.WriteLine("我比你先返回，哈哈");
}
~OK。
可以使用这个方式做我的FM登陆了。