重新想象 Windows 8.1 Store Apps (90) – 通信的新特性: 通过 HttpBaseProtocolFilter 实现 http 请求的缓存控制，以及 cookie 读写; 自定义 HttpFilter; 其他
作者：webabcd
介绍
重新想象 Windows 8.1 Store Apps 之通信的新特性
- 通过 HttpBaseProtocolFilter 控制缓存逻辑，以及如何通过 HttpBaseProtocolFilter 管理 cookie
- 自定义 HttpFilter
- 其他
示例
HTTP 服务端
WebServer/HttpDemo.aspx.cs
/*
* 用于响应 http 请求
*/using System;
using System.IO;
using System.Threading;
using System.Web;namespace WebServer
{
public partial class HttpDemo : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// 停 3 秒，以方便测试 http 请求的取消
Thread.Sleep(); var action = Request.QueryString["action"]; switch (action)
{
case "getString": // 响应 http get string
Response.Write("hello webabcd: " + DateTime.Now.ToString("hh:mm:ss"));
break;
case "getStream": // 响应 http get stream
Response.Write("hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd hello webabcd");
break;
case "postString": // 响应 http post string
Response.Write(string.Format("param1:{0}, param2:{1}, referrer:{2}", Request.Form["param1"], Request.Form["param2"], Request.UrlReferrer));
break;
case "postStream": // 响应 http post stream
using (StreamReader reader = new StreamReader(Request.InputStream))
{
if (Request.InputStream.Length > * )
{
// 接收的数据太大，则显示“数据接收成功”
Response.Write("数据接收成功");
}
else
{
// 显示接收到的数据
string body = reader.ReadToEnd();
Response.Write(Server.HtmlEncode(body));
}
}
break;
case "uploadFile": // 处理上传文件的请求
for (int i = ; i < Request.Files.Count; i++)
{
string key = Request.Files.GetKey(i);
HttpPostedFile file = Request.Files.Get(key);
string savePath = @"d:\" + file.FileName; // 保存文件
file.SaveAs(savePath); Response.Write(string.Format("key: {0}, fileName: {1}, savePath: {2}", key, file.FileName, savePath));
Response.Write("\n");
}
break;
case "outputCookie": // 用于显示服务端获取到的 cookie 信息
for (int i = ; i < Request.Cookies.Count; i++)
{
HttpCookie cookie = Request.Cookies[];
Response.Write(string.Format("cookieName: {0}, cookieValue: {1}", cookie.Name, cookie.Value));
Response.Write("\n");
}
break;
case "outputCustomHeader": // 用于显示一个自定义的 http header
Response.Write("myRequestHeader: " + Request.Headers["myRequestHeader"]);
break;
default:
break;
} Response.End();
}
}
}
1、演示如何通过 HttpBaseProtocolFilter 控制缓存逻辑，以及如何通过 HttpBaseProtocolFilter 管理 cookie
HttpBaseProtocolFilterDemo.xaml
<Page
x:Class="Windows81.Communication.HTTP.HttpBaseProtocolFilterDemo"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows81.Communication.HTTP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"> <Grid Background="Transparent">
<StackPanel Margin="120 0 0 0"> <TextBlock Name="lblMsg" FontSize="14.667" /> <Button Name="btnCacheControl" Content="通过 HttpBaseProtocolFilter 控制缓存逻辑" Click="btnCacheControl_Click" Margin="0 10 0 0" /> <Button Name="btnCookie" Content="通过 HttpBaseProtocolFilter 管理 cookie" Click="btnCookie_Click" Margin="0 10 0 0" /> </StackPanel>
</Grid>
</Page>
HttpBaseProtocolFilterDemo.xaml.cs
/*
* 演示如何通过 HttpBaseProtocolFilter 控制缓存逻辑，以及如何通过 HttpBaseProtocolFilter 管理 cookie
*
*
* 注：
* 1、HttpBaseProtocolFilter 实现了 IHttpFilter 接口（也就是说如果想要一个自定义 HttpFilter 的话，只要实现 IHttpFilter 接口即可）
* 2、本例仅演示通过 HttpBaseProtocolFilter 控制缓存逻辑以及管理 cookie，HttpBaseProtocolFilter 的其它功能请参见文档
*/using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
using Windows.Web.Http;
using Windows.Web.Http.Filters;namespace Windows81.Communication.HTTP
{
public sealed partial class HttpBaseProtocolFilterDemo : Page
{
private HttpClient _httpClient;
private HttpBaseProtocolFilter _filter; public HttpBaseProtocolFilterDemo()
{
this.InitializeComponent();
} protected override void OnNavigatedFrom(NavigationEventArgs e)
{
// 释放资源
if (_filter != null)
{
_filter.Dispose();
_filter = null;
} if (_httpClient != null)
{
_httpClient.Dispose();
_httpClient = null;
}
} // 演示如何通过 HttpBaseProtocolFilter 控制缓存逻辑
private async void btnCacheControl_Click(object sender, RoutedEventArgs e)
{
_filter = new HttpBaseProtocolFilter(); // 实例化 HttpClient 时，指定此 HttpClient 所关联的 IHttpFilter 对象
_httpClient = new HttpClient(_filter); try
{
// 获取到 http 响应的数据后写入缓存的行为
// NoCache - 不写入缓存
// Default - 默认行为，一般会写入缓存（默认值）
_filter.CacheControl.WriteBehavior = HttpCacheWriteBehavior.NoCache; // 请求 http 时，从缓存获取数据的逻辑
// Default - 使用 RFC 2616 中由 IETF 指定的缓存算法（默认值）
// MostRecent - 尽可能使用本地 HTTP 缓存，但应始终询问服务器是否有更新的内容可用
// OnlyFromCache - 只使用本地 HTTP 缓存中的数据，适合脱机的场景
_filter.CacheControl.ReadBehavior = HttpCacheReadBehavior.Default; HttpResponseMessage response = await _httpClient.GetAsync(new Uri("http://localhost:39630/HttpDemo.aspx?action=getString")); lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
lblMsg.Text += Environment.NewLine; lblMsg.Text += await response.Content.ReadAsStringAsync();
lblMsg.Text += Environment.NewLine;
}
catch (Exception ex)
{
lblMsg.Text += ex.ToString();
lblMsg.Text += Environment.NewLine;
}
} // 演示如何通过 HttpBaseProtocolFilter 管理 cookie
private async void btnCookie_Click(object sender, RoutedEventArgs e)
{
_httpClient = new HttpClient(); try
{
// 构造一个 cookie（需要指定 cookie 的 name, domain, path）
HttpCookie cookie = new HttpCookie("name", "localhost", "/");
cookie.Value = "webabcd";
cookie.Expires = DateTimeOffset.Now.AddDays();
cookie.Secure = false;
cookie.HttpOnly = false; // 通过 HttpBaseProtocolFilter 写入 cookie（也可以获取 cookie 或者删除 cookie）
HttpBaseProtocolFilter filter = new HttpBaseProtocolFilter();
bool replaced = filter.CookieManager.SetCookie(cookie, false); // 请求 http 时会带上相应的 cookie
HttpResponseMessage response = await _httpClient.GetAsync(new Uri("http://localhost:39630/HttpDemo.aspx?action=outputCookie")); lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
lblMsg.Text += Environment.NewLine; lblMsg.Text += await response.Content.ReadAsStringAsync();
lblMsg.Text += Environment.NewLine;
}
catch (Exception ex)
{
lblMsg.Text += ex.ToString();
lblMsg.Text += Environment.NewLine;
}
}
}
}
2、演示如何使用自定义的 HttpFilter
MyHttpFilter.cs
/*
* 实现 IHttpFilter 接口，开发一个自定义的 HttpFilter
*
*
* 本 HttpFilter 会在请求和响应的 http header 中添加一条自定义数据
*/using System;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Web.Http;
using Windows.Web.Http.Filters;namespace Windows81.Communication.HTTP
{
public class MyHttpFilter : IHttpFilter
{
private HttpBaseProtocolFilter _innerFilter; public MyHttpFilter()
{
_innerFilter = new HttpBaseProtocolFilter();
} // IHttpFilter 唯一的一个需要实现的方法
public IAsyncOperationWithProgress<HttpResponseMessage, HttpProgress> SendRequestAsync(HttpRequestMessage request)
{
return AsyncInfo.Run<HttpResponseMessage, HttpProgress>(async (cancellationToken, progress) =>
{
// 添加一个自定义 request http header
request.Headers.Add("myRequestHeader", "request webabcd"); // 借用 HttpBaseProtocolFilter 来完成 SendRequestAsync() 的工作
HttpResponseMessage response = await _innerFilter.SendRequestAsync(request).AsTask(cancellationToken, progress); cancellationToken.ThrowIfCancellationRequested(); // 添加一个自定义 response http header
response.Headers.Add("myResponseHeader", "response webabcd"); return response;
});
} public void Dispose()
{
_innerFilter.Dispose();
GC.SuppressFinalize(this);
}
}
}
CustomHttpFilter.xaml
<Page
x:Class="Windows81.Communication.HTTP.CustomHttpFilter"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows81.Communication.HTTP"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"> <Grid Background="Transparent">
<StackPanel Margin="120 0 0 0"> <TextBlock Name="lblMsg" FontSize="14.667" /> <Button Name="btnDemo" Content="自定义 HttpFilter" Click="btnDemo_Click" Margin="0 10 0 0" /> <Button Name="btnCancel" Content="cancel" Click="btnCancel_Click" Margin="0 10 0 0" /> </StackPanel>
</Grid>
</Page>
CustomHttpFilter.xaml.cs
/*
* 演示如何使用自定义的 HttpFilter
*
*
* 自定义 HttpFilter 需要实现 IHttpFilter 接口，请参见：MyHttpFilter.cs
*/using System;
using System.Threading;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
using Windows.Web.Http;namespace Windows81.Communication.HTTP
{
public sealed partial class CustomHttpFilter : Page
{
private HttpClient _httpClient;
private CancellationTokenSource _cts; // 自定义的 HttpFilter
private MyHttpFilter _filter; public CustomHttpFilter()
{
this.InitializeComponent();
} protected override void OnNavigatedFrom(NavigationEventArgs e)
{
// 释放资源
if (_filter != null)
{
_filter.Dispose();
_filter = null;
} if (_httpClient != null)
{
_httpClient.Dispose();
_httpClient = null;
} if (_cts != null)
{
_cts.Dispose();
_cts = null;
}
} private async void btnDemo_Click(object sender, RoutedEventArgs e)
{
_filter = new MyHttpFilter(); // 实例化 HttpClient 时，指定此 HttpClient 所关联的 IHttpFilter 对象
_httpClient = new HttpClient(_filter); _cts = new CancellationTokenSource(); try
{
HttpResponseMessage response = await _httpClient.GetAsync(new Uri("http://localhost:39630/HttpDemo.aspx?action=outputCustomHeader")).AsTask(_cts.Token); lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
lblMsg.Text += Environment.NewLine;
lblMsg.Text += "myResponseHeader: " + response.Headers["myResponseHeader"];
lblMsg.Text += Environment.NewLine; // IHttpContent.ReadAsStringAsync() - 获取 string 类型的响应数据
// IHttpContent.ReadAsBufferAsync() - 获取 IBuffer 类型的响应数据
// IHttpContent.ReadAsInputStreamAsync() - 获取 IInputStream 类型的响应数据
lblMsg.Text += await response.Content.ReadAsStringAsync();
lblMsg.Text += Environment.NewLine;
}
catch (TaskCanceledException)
{
lblMsg.Text += "取消了";
lblMsg.Text += Environment.NewLine;
}
catch (Exception ex)
{
lblMsg.Text += ex.ToString();
lblMsg.Text += Environment.NewLine;
}
} private void btnCancel_Click(object sender, RoutedEventArgs e)
{
// 取消 http 请求
if (_cts != null)
{
_cts.Cancel();
_cts.Dispose();
_cts = null;
}
}
}
}
3、其他
Other.xaml
<Page
x:Class="Windows81.Communication.Other"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows81.Communication"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"> <Grid Background="Transparent">
<StackPanel Margin="120 0 0 0"> <TextBlock Name="lblMsg" FontSize="14.667" TextWrapping="Wrap">
<Run>1、实时通信支持 Windows.Web.Http API 了（仍然要求 app 必须在锁屏上），关于实时通信请参见：http://www.cnblogs.com/webabcd/archive/2013/10/28/3391694.html</Run>
<LineBreak />
<Run>2、增加了对 Geofence 的支持，即某设备在进入或退出某地理区域后可以向 app 发出通知。Windows.Devices.Geolocation.Geofencing 命名空间用于 Geofence 管理， LocationTrigger 用于后台任务触发 Geofence 事件</Run>
<LineBreak />
<Run>3、支持设备的 WiFi 直连，参见 Windows.Devices.WifiDirect 命名空间</Run>
</TextBlock> </StackPanel>
</Grid>
</Page>
OK
[源码下载]
