如何在 MVC 项目中使用 linqtotwitter 搜索推文

Question

如何在 MVC 项目中使用 linqtotwitter 搜索推文，并将其从控制台转换为 MVC。

var searchResponse =
            await
            (from search in twitterCtx.Search
             where search.Type == SearchType.Search &&
                   search.Query == "\"LINQ to Twitter\""
             select search)
            .SingleOrDefaultAsync();

        if (searchResponse != null && searchResponse.Statuses != null)
            searchResponse.Statuses.ForEach(tweet =>
                Console.WriteLine(
                    "User: {0}, Tweet: {1}", 
                    tweet.User.ScreenNameResponse,
                    tweet.Text));

Answer 1

MVC 的主要作用是使用正确的授权者。我使用的技术是一个单独的控制器来处理 OAuth，如下所示：

using System;
using System.Configuration;
using System.Linq;
using System.Threading.Tasks;
using System.Web.Mvc;
using LinqToTwitter;

namespace MvcDemo.Controllers
{
    public class OAuthController : AsyncController
    {
        public ActionResult Index()
        {
            return View();
        }

        public async Task<ActionResult> BeginAsync()
        {
            //var auth = new MvcSignInAuthorizer
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore
                {
                    ConsumerKey = ConfigurationManager.AppSettings["consumerKey"],
                    ConsumerSecret = ConfigurationManager.AppSettings["consumerSecret"]
                }
            };

            string twitterCallbackUrl = Request.Url.ToString().Replace("Begin", "Complete");
            return await auth.BeginAuthorizationAsync(new Uri(twitterCallbackUrl));
        }

        public async Task<ActionResult> CompleteAsync()
        {
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore()
            };

            await auth.CompleteAuthorizeAsync(Request.Url);

            // This is how you access credentials after authorization.
            // The oauthToken and oauthTokenSecret do not expire.
            // You can use the userID to associate the credentials with the user.
            // You can save credentials any way you want - database, 
            //   isolated storage, etc. - it's up to you.
            // You can retrieve and load all 4 credentials on subsequent 
            //   queries to avoid the need to re-authorize.
            // When you've loaded all 4 credentials, LINQ to Twitter will let 
            //   you make queries without re-authorizing.
            //
            //var credentials = auth.CredentialStore;
            //string oauthToken = credentials.OAuthToken;
            //string oauthTokenSecret = credentials.OAuthTokenSecret;
            //string screenName = credentials.ScreenName;
            //ulong userID = credentials.UserID;
            //

            return RedirectToAction("Index", "Home");
        }
    }
}

请注意，这是一个 MvcAuthorizer 和一个 SessionStateCredentialStore。此外，请记住确保您的状态服务器正在运行，这样它就不会在 IIS 回收期间任意转储您的会话状态。所以现在，当您需要检测用户是否未经授权时，请将其发送到OAuthController，如下所示：

using LinqToTwitter;
using System.Web.Mvc;

namespace MvcDemo.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            if (!new SessionStateCredentialStore().HasAllCredentials())
                return RedirectToAction("Index", "OAuth");

            return View();
        }
    }
}

一旦用户获得授权，您就可以在操作方法中执行任何 LINQ to Twitter 查询，如下所示：

using System;
using System.Linq;
using System.Threading.Tasks;
using System.Web.Mvc;
using MvcDemo.Models;
using LinqToTwitter;
using System.Collections.Generic;

namespace MvcDemo.Controllers
{
    public class StatusDemosController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult Tweet()
        {
            var sendTweetVM = new SendTweetViewModel
            {
                Text = "Testing async LINQ to Twitter in MVC - " + DateTime.Now.ToString()
            };

            return View(sendTweetVM);
        }

        [HttpPost]
        [ActionName("Tweet")]
        public async Task<ActionResult> TweetAsync(SendTweetViewModel tweet)
        {
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore()
            };

            var ctx = new TwitterContext(auth);

            Status responseTweet = await ctx.TweetAsync(tweet.Text);

            var responseTweetVM = new SendTweetViewModel
            {
                Text = "Testing async LINQ to Twitter in MVC - " + DateTime.Now.ToString(),
                Response = "Tweet successful! Response from Twitter: " + responseTweet.Text
            };

            return View(responseTweetVM);
        }

        [ActionName("HomeTimeline")]
        public async Task<ActionResult> HomeTimelineAsync()
        {
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore()
            };

            var ctx = new TwitterContext(auth);

            var tweets =
                await
                (from tweet in ctx.Status
                 where tweet.Type == StatusType.Home
                 select new TweetViewModel
                 {
                     ImageUrl = tweet.User.ProfileImageUrl,
                     ScreenName = tweet.User.ScreenNameResponse,
                     Text = tweet.Text
                 })
                .ToListAsync();

            return View(tweets);
        }

        [ActionName("Search")]
        public async Task<ActionResult> SearchAsync()
        {
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore()
            };

            var ctx = new TwitterContext(auth);

            var searchResponse =
                await
                (from search in twitterCtx.Search
                 where search.Type == SearchType.Search &&
                       search.Query == "\"LINQ to Twitter\""
                 select search)
                .SingleOrDefaultAsync();

            return View(searchResponse.Statuses);
        }

        [ActionName("UploadImage")]
        public async Task<ActionResult> UploadImageAsync()
        {
            var auth = new MvcAuthorizer
            {
                CredentialStore = new SessionStateCredentialStore()
            };

            var twitterCtx = new TwitterContext(auth);

            string status = $"Testing multi-image tweet #Linq2Twitter £ {DateTime.Now}";
            string mediaCategory = "tweet_image";

            string path = Server.MapPath("..\\Content\\200xColor_2.png");
            var imageUploadTasks =
                new List<Task<Media>>
                {
                    twitterCtx.UploadMediaAsync(System.IO.File.ReadAllBytes(path), "image/jpg", mediaCategory),
                };

            await Task.WhenAll(imageUploadTasks);

            List<ulong> mediaIds =
                (from tsk in imageUploadTasks
                 select tsk.Result.MediaID)
                .ToList();

            Status tweet = await twitterCtx.TweetAsync(status, mediaIds);

            return View(
                new TweetViewModel
                {
                    ImageUrl = tweet.User.ProfileImageUrl,
                    ScreenName = tweet.User.ScreenNameResponse,
                    Text = tweet.Text
                });
        }
    }
}

我在那里手动编码了您的搜索查询，但看看它如何使用MvcAuthorizer。 SessionStateCredentialStore 从 Session 状态拉取之前获得的凭据。

如果您不喜欢 Session 状态，请在您想要保存凭据的位置实现 ICredentialStore。

您还可以找到有效的MVC demo on the LINQ to Twitter GitHub site 的代码。