Reddit.NET OAuth认证失败：MissingMethodException错误求助

问题 #

使用Reddit.NET库实现OAuth认证时触发System.MissingMethodException，提示找不到RestSharp.IRestRequest的AddHeader方法。已确认重定向地址http://localhost:8080/Reddit.NET/oauthRedirect配置正确，AppID与AppSecret无误。

相关代码：

public class RedditManager
{
    private readonly RedditClient _redditClient;
    public RedditManager(string appID, string appSecret)
    {
        string refreshToken = AuthorizeUser(appID, appSecret);
        _redditClient = new RedditClient(appID, refreshToken, appSecret);
    }
        
    public static string AuthorizeUser(string appId, string appSecret = null, int port = 8080)
    {
        // Create a new instance of the auth token retrieval library.  --Kris
        AuthTokenRetrieverLib authTokenRetrieverLib = new AuthTokenRetrieverLib(appId, appSecret, port);

        // Start the callback listener.  --Kris
        // Note - Ignore the logging exception message if you see it.  You can use Console.Clear() after this call to get rid of it if you're running a console app.
        authTokenRetrieverLib.AwaitCallback();

        // Open the browser to the Reddit authentication page.  Once the user clicks "accept", Reddit will redirect the browser to localhost:8080, where AwaitCallback will take over.  --Kris
        OpenBrowser(authTokenRetrieverLib.AuthURL());

        // Replace this with whatever you want the app to do while it waits for the user to load the auth page and click Accept.  --Kris
        while (true) { }

        // Cleanup.  --Kris
        authTokenRetrieverLib.StopListening();

        return authTokenRetrieverLib.RefreshToken;
    }

    private static void OpenBrowser(string authUrl, string browserPath = @"C:\Program Files\BraveSoftware\Brave-Browser\Application\brave.exe")
    {
        try
        {
            ProcessStartInfo processStartInfo = new ProcessStartInfo(authUrl);
            Process.Start(processStartInfo);
        }
        catch (System.ComponentModel.Win32Exception)
        {
            // This typically occurs if the runtime doesn't know where your browser is.  Use BrowserPath for when this happens.  --Kris
            ProcessStartInfo processStartInfo = new ProcessStartInfo(browserPath)
            {
                Arguments = authUrl
            };
            Process.Start(processStartInfo);
        }
        }
    public Task HotPosts(string subreddit)
    {
        var posts = _redditClient.Subreddit(subreddit).Posts.Hot;
        List<Post> videoposts = new List<Post>();
        foreach (var post in posts)
        {
            if (post.Permalink.Contains(".mp4"))
            {
                videoposts.Add(post);
            }
        }
        foreach (var post in videoposts)
        {
           Console.WriteLine(post.Info());
        }
        return Task.CompletedTask;
    }
}

控制台错误日志：

2024-01-24 11:40:27 [INFO]  (uhttpsharp.HttpServer) Embedded uhttpserver started. 2024-01-24 11:40:37 [INFO]  (uhttpsharp.HttpClientHandler) Got Client 127.0.0.1:59132 2024-01-24 11:40:37 [INFO]  (uhttpsharp.HttpServer) Embedded uhttpserver stopped. 2024-01-24 11:40:37 [INFO]  (uhttpsharp.HttpClientHandler) 127.0.0.1:59132 : Got request /Reddit.NET/oauthRedirect 2024-01-24 11:40:37 [WARN]  (uhttpsharp.HttpClientHandler) Error while serving : 127.0.0.1:59132 System.MissingMethodException Method not found: 'RestSharp.IRestRequest RestSharp.RestRequest.AddHeader(System.String, System.String)'. at Reddit.AuthTokenRetriever.AuthTokenRetrieverLib.<>c__DisplayClass37_0.<AwaitCallback>b__0(IHttpContext context, Func`1 next)
at uhttpsharp.AnonymousHttpRequestHandler.Handle(IHttpContext context, Func`1 next) at uhttpsharp.RequestHandlersAggregateExtensions.<>c__DisplayClass1_0.<Aggregate>b__0(IHttpContext context) at uhttpsharp.HttpClientHandler.<Process>d__11.MoveNext() 2024-01-24 11:40:37 [INFO]  (uhttpsharp.HttpClientHandler) Lost Client 127.0.0.1:59132

解决方案 #

错误原因 #

该异常是RestSharp版本不兼容导致的：Reddit.NET依赖的RestSharp版本中，AddHeader方法的返回值类型或签名与你项目中当前引用的RestSharp版本不匹配。例如旧版RestSharp的AddHeader返回void，而Reddit.NET预期的版本中该方法返回IRestRequest，运行时因找不到对应签名的方法而抛出异常。

解决步骤 #

• 统一RestSharp版本：卸载当前项目中的RestSharp包，重新安装与Reddit.NET兼容的版本。在NuGet包管理器控制台执行：

  Uninstall-Package RestSharp
  Install-Package RestSharp -Version [Reddit.NET依赖的版本号]
  

  可通过查看Reddit.NET的NuGet依赖信息，获取它要求的RestSharp版本范围，选择该范围内的版本安装。
• 清理重建项目：执行解决方案的Clean Solution操作，再执行Rebuild Solution，确保所有依赖项正确加载并编译。
• 排查依赖冲突：如果项目中其他第三方库也引用了RestSharp，需通过NuGet依赖管理功能统一所有库使用的RestSharp版本，避免版本不一致引发的冲突。

内容的提问来源于stack exchange，提问作者VindE