Xamarin.Auth - Foursquare venue API 的“发生一个或多个错误”

所以我基本上是在尝试使用Foursquare的场地API的东西，但是每当我发送API请求时都会收到奇怪的错误。

首先，我使用以下代码进行身份验证;

var foursquareClient = new FoursquareClient(this);
        if(!foursquareClient.IsAuthenticated)
            foursquareClient.Authenticate();`

认证码;

public void Authenticate()
    {
        Log.Verbose(Logging.AppTag, "FourSquareClient:Authenticate()");
        if (this.IsAuthenticated)
        {
            Log.Debug(Logging.AppTag, "FourSquareClient is already authenticated! ");
            return;
        }
        this._authenticator = new OAuth2Authenticator(
            clientId: ClientId,
            scope: "",
            authorizeUrl: new Uri("https://foursquare.com/oauth2/authenticate"),
            redirectUrl: new Uri("http://www.int6.org"))
        {
            AllowCancel = false
        };
        this._authenticator.Completed += (sender, eventArgs) =>
        {
            if (eventArgs.IsAuthenticated) // auth. completed.
            {
                this.StoreAccount(eventArgs);
                var builder = new AlertDialog.Builder(this.OwnerContext);
                builder.SetMessage("auth all good!");
                builder.SetPositiveButton("Ok", (o, e) => { });
                builder.Create().Show();
                return;
            }
            else // The user cancelled.
            {
                var builder = new AlertDialog.Builder(this.OwnerContext);
                builder.SetMessage("User canncelled!");
                builder.SetPositiveButton("Ok", (o, e) => { });
                builder.Create().Show();
                return;
            }
        };
        // show the authenticator UI and start auth.
        var intent = this._authenticator.GetUI(this.OwnerContext);
        this.OwnerContext.StartActivity(intent);
    }

因此，如果用户通过一次身份验证，它将帐户存储在设备上。

public FoursquareClient(Context context)
{
    Log.Verbose(Logging.AppTag, "Init foursquare client..");
    this.OwnerContext = context; // make sure we set the owner context before any.
    this.RetrieveAccount(); // try to retrieve any existing accounts.
}

每当他再次打开应用程序时，该帐户将被加载回;

private void RetrieveAccount()
{
    if (this.IsAuthenticated)
    {
        Log.Debug(Logging.AppTag, "FourSquareClient is already authenticated! ");
        return;
    }
    var accounts = AccountStore.Create(this.OwnerContext).FindAccountsForService("Foursquare");
    var enumerable = accounts as IList<Account> ?? accounts.ToList();
    if (enumerable.Any())
    {
        Log.Info(Logging.AppTag, "Foursquareclient found account data.");
        this.IsAuthenticated = true;
        this.Account = enumerable.First();
    }
    else
    {
        Log.Info(Logging.AppTag, "Foursquareclient no account data found!");
        this.IsAuthenticated = false;
        this.Account = null;
    }
}

所以我想我对身份验证的东西很好，但不知何故无法提出请求;

public string MakeRequest()
{
    var @params = new Dictionary<string, string>
        {
            {"v", "20120321"},
            {"ll", "44.3,37.2"}
        };
    var request = new OAuth2Request("GET", new Uri("https://api.foursquare.com/v2/venues/explore"), @params,
                                    this.Account);
    request.GetResponseAsync().ContinueWith(t =>
        {
            if (t.IsFaulted)
                Console.WriteLine(t.Exception.Flatten()); 
            else
            {
                string json = t.Result.GetResponseText();
                Console.WriteLine(json);
            }
        });
    return string.Empty;
}

请求代码返回;发生一个或多个错误

10-02 14：54：31.403 I/mono-stdout( 8641(： System.AggregateException： ---> System.Net.WebException： 远程服务器返回错误： (400( 错误请求。 系统聚合异常：--->发生一个或多个错误 System.Net.WebException： 远程服务器返回错误： (400( 错误请求。10-02 14：54：31.413 I/单声道标准输出(8641(： at System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult 结果( [0x00000] 在 ：0 在 System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult 结果( [0x00000] 在 ：0 在 System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data([0x00000] in ：0 10-02 14：54：31.413 I/单声道标准输出(8641(： at System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data([0x00000] in ：0 10-02 14：54：31.413 I/单声道标准输出(8641(： --- 内部异常结束 堆栈跟踪 --- --- 内部异常堆栈跟踪结束--- --> (内部异常 0(System.Net.WebException：远程服务器 返回错误：(400( 错误请求。10-02 14:54:31.423 I/单标准输出( 8641(： --> (内部异常 0( System.Net.WebException： 远程服务器返回错误： (400( 错误请求。10-02 14：54：31.423 I/单声道标准输出(8641(： at System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult 结果( [0x00000] 在 ：0 在 System.Net.HttpWebRequest.CheckFinalStatus (System.Net.WebAsyncResult 结果( [0x00000] 在 ：0 10-02 14:54:31.423 I/mono-stdout( 8641(： at System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data([0x00000] in ：0 at System.Net.HttpWebRequest.SetResponseData (System.Net.WebConnectionData data([0x00000] in ：0

关于我错过了什么的任何想法？

        // https://developer.foursquare.com/docs/venues/explore
    public string GetVenues()
    {
        var @params = new Dictionary<string, string>
            {
                {"v", "20120321"},
                {"ll", "44.3,37.2"}
            };
        var response = this.Request("venues/explore", @params);
        return response;
    }
    private string Request(string endpoint, Dictionary<string, string> @params = null, HttpMethod httpMethod = HttpMethod.GET, bool userless = false)
    {
        var client = new RestClient("https://api.foursquare.com/v2/");            
        var request = new RestRequest(endpoint, Method.GET);
        if (!userless)
        {
            // About userless requests - https://developer.foursquare.com/overview/auth.html - Some of our endpoints that don’t pertain to 
            // specific user information, such as venues search are enabled for userless access (meaning you don’t need to have a user auth your 
            // app for access). To make a userless request, specify your consumer key's Client ID and Secret instead of an auth token in the request URL.
            request.AddParameter("oauth_token", this.Account.Properties["access_token"]);
        }
        if (@params != null)
        {
            foreach (var param in @params)
            {
                request.AddParameter(param.Key, param.Value);
            }
        }
        var response = client.Execute(request);
        var content = response.Content; // raw content as string
        return content;
    }

var @params = new Dictionary<string, string>
        {
            {"oauth_token", this.Account.Properties["access_token"]},
            {"v", "20120321"},
            {"ll", "44.3,37.2"}
        };