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

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]

秒客网

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

相关文章