從新想象 Windows 8.1 Store Apps (88) - 通訊的新特性: 新的 HttpClient

時間 2019-11-18

標籤從新想象 windows 8.1 store apps 通訊特性新的 httpclient 欄目 Windows 简体版

原文原文鏈接

做者：webabcd

介紹
從新想象 Windows 8.1 Store Apps 之通訊的新特性html5

新的 HttpClient
http get string
http get stream
http post string
http post stream

示例
HTTP 服務端
WebServer/HttpDemo.aspx.csios

/*
 * 用於響應 http 請求
 */

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，以方便測試 http 請求的取消
            Thread.Sleep(3000);

            var action = Request.QueryString["action"];

            switch (action)
            {
                case "getString": // 響應 http get string 
                    Response.Write("hello webabcd: " + DateTime.Now.ToString("hh:mm:ss"));
                    break;
                case "getStream": // 響應 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": // 響應 http post string 
                    Response.Write(string.Format("param1:{0}, param2:{1}, referrer:{2}", Request.Form["param1"], Request.Form["param2"], Request.UrlReferrer));
                    break;
                case "postStream": // 響應 http post stream 
                    using (StreamReader reader = new StreamReader(Request.InputStream))
                    {
                        if (Request.InputStream.Length > 1024 * 100)
                        {
                            // 接收的數據太大，則顯示「數據接收成功」
                            Response.Write("數據接收成功");
                        }
                        else
                        {
                            // 顯示接收到的數據
                            string body = reader.ReadToEnd();
                            Response.Write(Server.HtmlEncode(body));
                        }
                    } 
                    break;
                case "uploadFile": // 處理上傳文件的請求
                    for (int i = 0; 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": // 用於顯示服務端獲取到的 cookie 信息
                    for (int i = 0; i < Request.Cookies.Count; i++)
                    {
                        HttpCookie cookie = Request.Cookies[0];
                        Response.Write(string.Format("cookieName: {0}, cookieValue: {1}", cookie.Name, cookie.Value));
                        Response.Write("\n");
                    }
                    break;
                case "outputCustomHeader": // 用於顯示一個自定義的 http header
                    Response.Write("myRequestHeader: " + Request.Headers["myRequestHeader"]);
                    break;
                default:
                    break;
            }

            Response.End();
        }
    }
}

一、演示新的 HttpClient
Summary.xaml.csweb

/*
 * 本例簡要說明新的命名空間 Windows.Web.Http 下的新的 HttpClient 的用法（其餘相關類也均來自新的 Windows.Web.Http 命名空間）
 * 經過 HttpClient, HttpRequestMessage, HttpResponseMessage 實現 HTTP 通訊
 * 
 * 
 * 在 win8.1 中加強了 HttpClient 的功能並將此加強版的 HttpClient 轉移至了 Windows.Web.Http 命名空間下（原 win8 的 HttpClient 在 System.Net.Http 命名空間下，依舊可用）
 * 一、若是要查看 System.Net.Http 命名空間下的 HttpClient 的用法請參見：http://www.cnblogs.com/webabcd/archive/2013/09/23/3334233.html
 * 二、關於支持 OAuth 2.0 驗證的客戶端也請參見：http://www.cnblogs.com/webabcd/archive/2013/09/23/3334233.html
 * 
 * 
 * HttpClient - 用於發起 http 請求，以及接收 http 響應
 *     GetStringAsync(), GetAsync(), GetBufferAsync(), GetInputStreamAsync() - http get 請求
 *     DeleteAsync() - http delete 請求
 *     PostAsync(), PutAsync() - http post/put 請求
 *         參數：IHttpContent content - http 請求的數據
 *             實現了 IHttpContent 的類有：HttpStringContent, HttpBufferContent, HttpStreamContent, HttpFormUrlEncodedContent, HttpMultipartFormDataContent 等
 *         參數：HttpCompletionOption completionOption（HttpCompletionOption 枚舉）
 *             ResponseContentRead - 獲取到所有內容後再返回數據，默認值
 *             ResponseHeadersRead - 獲取到頭信息後就返回數據，用於流式獲取
 *     SendRequestAsync() - 根據指定的 HttpRequestMessage 對象發起請求
 * 
 * HttpRequestMessage - http 請求
 *     Method - http 方法
 *     RequestUri - 請求的 uri
 *     Headers - http 的請求頭信息
 *     Properties - 當作上下文用
 *     Content - http 請求的內容（IHttpContent 類型）
 *         實現了 IHttpContent 的類有：HttpStringContent, HttpBufferContent, HttpStreamContent, HttpFormUrlEncodedContent, HttpMultipartFormDataContent 等
 *     TransportInformation - 獲取一個 HttpTransportInformation 類型的對象，用於 https 相關
 *         
 * HttpResponseMessage - http 響應
 *     RequestMessage - 對應的 HttpRequestMessage 對象
 *     Headers - http 的響應頭信息
 *     Version - http 版本，默認是 1.1
 *     Source - 數據來源（HttpResponseMessageSource 枚舉：Cache 或 Network）
 *     StatusCode - http 響應的狀態碼
 *     ReasonPhrase - http 響應的狀態碼所對應的短語
 *     IsSuccessStatusCode - http 響應的狀態碼是不是成功的值（200-299）
 *     EnsureSuccessStatusCode() - 當 IsSuccessStatusCode 爲 false 時會拋出異常
 *     
 * 
 * 另：
 * win8 metro 的 http 抓包可用 fiddler
 * 
 * 還有：
 * http 通訊還能夠經過以下方法實現
 * HttpWebRequest webRequest = WebRequest.Create(url);
 */

using System;
using System.Collections.Generic;
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 Summary : Page
    {
        private HttpClient _httpClient;
        private CancellationTokenSource _cts;

        public Summary()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            // 釋放資源
            if (_httpClient != null)
            {
                _httpClient.Dispose();
                _httpClient = null;
            }

            if (_cts != null)
            {
                _cts.Dispose();
                _cts = null;
            }
        }

        private async void btnPost_Click(object sender, RoutedEventArgs e)
        {
            _httpClient = new HttpClient();
            _cts = new CancellationTokenSource();

            try
            {
                string url = "http://localhost:39630/HttpDemo.aspx?action=postString";
                // 建立一個 HttpRequestMessage 對象
                HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, new Uri(url));

                // 須要 post 的數據
                HttpFormUrlEncodedContent postData = new HttpFormUrlEncodedContent(
                    new List<KeyValuePair<string, string>>
                    {
                        new KeyValuePair<string, string>("param1", "web"),
                        new KeyValuePair<string, string>("param2", "abcd")
                    }
                );

                // http 請求的數據
                request.Content = postData;
                // http 請求的頭信息（嘰歪一個，終於把 Referrer 改爲 Referer 了）
                request.Headers.Referer = new Uri("http://webabcd.cnblogs.com");

                // 請求 HttpRequestMessage 對象，並返回 HttpResponseMessage 數據
                HttpResponseMessage response = await _httpClient.SendRequestAsync(request).AsTask(_cts.Token); // 取消請求的方式改成經過 CancellationTokenSource 來實現了

                // http 響應的狀態碼及其對應的短語
                lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
                lblMsg.Text += Environment.NewLine;

                // 以字符串的方式獲取響應數據
                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 請求
            if (_cts != null)
            {
                _cts.Cancel();
                _cts.Dispose();
                _cts = null;
            }
        }
    }
}

二、演示 http get string
GetString.xaml.cswindows

/*
 * 演示 http get string
 */

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 GetString : Page
    {
        private HttpClient _httpClient;
        private CancellationTokenSource _cts;

        public GetString()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            // 釋放資源
            if (_httpClient != null)
            {
                _httpClient.Dispose();
                _httpClient = null;
            }

            if (_cts != null)
            {
                _cts.Dispose();
                _cts = null;
            }
        }

        private async void btnGetString_Click(object sender, RoutedEventArgs e)
        {
            _httpClient = new HttpClient();
            _cts = new CancellationTokenSource();

            try
            {
                HttpResponseMessage response = await _httpClient.GetAsync(new Uri("http://localhost:39630/HttpDemo.aspx?action=getString")).AsTask(_cts.Token); // 取消請求的方式改成經過 CancellationTokenSource 來實現了

                lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
                lblMsg.Text += Environment.NewLine;

                // IHttpContent.ReadAsStringAsync() - 獲取 string 類型的響應數據
                // IHttpContent.ReadAsBufferAsync() - 獲取 IBuffer 類型的響應數據
                // IHttpContent.ReadAsInputStreamAsync() - 獲取 IInputStream 類型的響應數據
                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 請求
            if (_cts != null)
            {
                _cts.Cancel();
                _cts.Dispose();
                _cts = null;
            }
        }
    }
}

三、演示 http get stream
GetStream.xaml.cscookie

/*
 * 演示 http get stream
 */

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Windows.Security.Cryptography;
using Windows.Storage.Streams;
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 GetStream : Page
    {
        private HttpClient _httpClient;
        private CancellationTokenSource _cts;

        public GetStream()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            // 釋放資源
            if (_httpClient != null)
            {
                _httpClient.Dispose();
                _httpClient = null;
            }

            if (_cts != null)
            {
                _cts.Dispose();
                _cts = null;
            }
        }

        private async void btnGetStream_Click(object sender, RoutedEventArgs e)
        {
            _httpClient = new HttpClient();
            _cts = new CancellationTokenSource();

            try
            {
                // HttpCompletionOption.ResponseHeadersRead - 獲取到頭信息後就返回數據，用於流式獲取
                HttpResponseMessage response = await _httpClient.GetAsync(
                    new Uri("http://localhost:39630/HttpDemo.aspx?action=getStream"),
                    HttpCompletionOption.ResponseHeadersRead).AsTask(_cts.Token); // 取消請求的方式改成經過 CancellationTokenSource 來實現了

                lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
                lblMsg.Text += Environment.NewLine;

                // IHttpContent.ReadAsStringAsync() - 獲取 string 類型的響應數據
                // IHttpContent.ReadAsBufferAsync() - 獲取 IBuffer 類型的響應數據
                // IHttpContent.ReadAsInputStreamAsync() - 獲取 IInputStream 類型的響應數據
                using (Stream responseStream = (await response.Content.ReadAsInputStreamAsync()).AsStreamForRead())
                {
                    byte[] buffer = new byte[32];
                    int read = 0;

                    while ((read = await responseStream.ReadAsync(buffer, 0, buffer.Length)) > 0)
                    {
                        lblMsg.Text += "讀取的字節數: " + read.ToString();
                        lblMsg.Text += Environment.NewLine;

                        IBuffer responseBuffer = CryptographicBuffer.CreateFromByteArray(buffer);
                        lblMsg.Text += CryptographicBuffer.EncodeToHexString(responseBuffer);
                        lblMsg.Text += Environment.NewLine;

                        buffer = new byte[32];
                    }
                }
            }
            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 請求
            if (_cts != null)
            {
                _cts.Cancel();
                _cts.Dispose();
                _cts = null;
            }
        }
    }
}

四、演示 http post string
PostString.xaml.csapp

/*
 * 演示 http post string
 */

using System;
using System.Collections.Generic;
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 PostString : Page
    {
        private HttpClient _httpClient;
        private CancellationTokenSource _cts;

        public PostString()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            // 釋放資源
            if (_httpClient != null)
            {
                _httpClient.Dispose();
                _httpClient = null;
            }

            if (_cts != null)
            {
                _cts.Dispose();
                _cts = null;
            }
        }

        private async void btnPostString_Click(object sender, RoutedEventArgs e)
        {
            _httpClient = new HttpClient();
            _cts = new CancellationTokenSource();

            try
            {
                // 須要 post 的數據
                var postData = new HttpFormUrlEncodedContent(
                    new List<KeyValuePair<string, string>>
                    {
                        new KeyValuePair<string, string>("param1", "web"),
                        new KeyValuePair<string, string>("param2", "abcd")
                    }
                );

                HttpResponseMessage response = await _httpClient.PostAsync(
                    new Uri("http://localhost:39630/HttpDemo.aspx?action=postString"),
                    postData).AsTask(_cts.Token); // 取消請求的方式改成經過 CancellationTokenSource 來實現了

                lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
                lblMsg.Text += Environment.NewLine;

                // HttpContent.ReadAsStringAsync() - 以 string 方式獲取響應數據
                // HttpContent.ReadAsByteArrayAsync() - 以 byte[] 方式獲取響應數據
                // HttpContent.ReadAsStreamAsync() - 以 stream 方式獲取響應數據
                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 請求
            if (_cts != null)
            {
                _cts.Cancel();
                _cts.Dispose();
                _cts = null;
            }
        }
    }
}

五、演示 http post stream
PostStream.xaml.csasp.net

/*
 * 演示 http post stream
 */

using System;
using System.IO;
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 PostStream : Page
    {
        private HttpClient _httpClient;
        private CancellationTokenSource _cts;

        public PostStream()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            // 釋放資源
            if (_httpClient != null)
            {
                _httpClient.Dispose();
                _httpClient = null;
            }

            if (_cts != null)
            {
                _cts.Dispose();
                _cts = null;
            }
        }

        private async void btnPostStream_Click(object sender, RoutedEventArgs e)
        {
            _httpClient = new HttpClient();
            _cts = new CancellationTokenSource();

            try
            {
                // 須要 post 的 stream 數據
                Stream stream = GenerateSampleStream(128);
                HttpStreamContent streamContent = new HttpStreamContent(stream.AsInputStream());

                HttpResponseMessage response = await _httpClient.PostAsync(
                   new Uri("http://localhost:39630/HttpDemo.aspx?action=postStream"),
                   streamContent).AsTask(_cts.Token);// 取消請求的方式改成經過 CancellationTokenSource 來實現了

                lblMsg.Text += ((int)response.StatusCode) + " " + response.ReasonPhrase;
                lblMsg.Text += Environment.NewLine;

                // IHttpContent.ReadAsStringAsync() - 獲取 string 類型的響應數據
                // IHttpContent.ReadAsBufferAsync() - 獲取 IBuffer 類型的響應數據
                // IHttpContent.ReadAsInputStreamAsync() - 獲取 IInputStream 類型的響應數據
                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;
            }
        }

        // 生成一個指定大小的內存流
        private static MemoryStream GenerateSampleStream(int size)
        {
            byte[] subData = new byte[size];
            for (int i = 0; i < subData.Length; i++)
            {
                subData[i] = (byte)(97 + i % 26); // a-z
            }

            return new MemoryStream(subData);
        }

        private void btnCancel_Click(object sender, RoutedEventArgs e)
        {
            // 取消 http 請求
            if (_cts != null)
            {
                _cts.Cancel();
                _cts.Dispose();
                _cts = null;
            }
        }
    }
}

OK
[源碼下載]async

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