如何通过instagram为我的xamarin表单应用程序验证用户身份？

Question

目前，我想对我的应用程序进行身份验证，并且只通过电子邮件（已经完成）和instagram进行身份验证，我已经从github存储库下载了代码，对我有很大帮助，除了在您要对其进行身份验证的那一刻，它标志着非技术性错误，而不是说“糟糕！发生了错误”的任何内容。

我下载的代码如下：

https://github.com/CrossGeeks/SocialMediaAuthenticationSample

在创建该存储库时保留其代码，显然将重点更多地放在instagram遵循的流程上，并仅修改一些声明为适合我的项目的常量。

const string InstagramApiUrl = "https://api.instagram.com";
const string InstagramScope = "basic";
const string InstagramAuthorizationUrl = "https://api.instagram.com/oauth/authorize/";
const string InstagramRedirectUrl = "https://xamboy.com/default.html";  
const string InstagramClientId = "<Client ID>";   ------ my change

这是我尝试使用C＃访问instagram的功能

async Task LoginInstagramAsync(AuthNetwork authNetwork)
        {
            EventHandler<string> onSuccessDelegate = null;
            EventHandler<string> onErrorDelegate = null;
            EventHandler onCancelDelegate = null;

            onSuccessDelegate = async (s, a) =>
            {

               UserDialogs.Instance.ShowLoading("Loading");

                var userResponse = await RestService.For<IInstagramApi>(InstagramApiUrl).GetUser(a);

                if (userResponse.IsSuccessStatusCode)
                {
                    var userDataString = await userResponse.Content.ReadAsStringAsync();
                    //Handling Encoding
                    var userDataStringFixed = System.Text.RegularExpressions.Regex.Unescape(userDataString);

                    var instagramUser = JsonConvert.DeserializeObject<InstagramUser>(userDataStringFixed);
                    var socialLoginData = new NetworkAuthData
                    {
                        Logo = authNetwork.Icon,
                        Picture = instagramUser.Data.ProfilePicture,
                        Foreground = authNetwork.Foreground,
                        Background = authNetwork.Background,
                        Name = instagramUser.Data.FullName,
                        Id = instagramUser.Data.Id
                    };

                    UserDialogs.Instance.HideLoading();
                    await App.Current.MainPage.Navigation.PushModalAsync(new HomePage(socialLoginData));
                }
                else
                {
                    //TODO: Handle instagram user info error
                   UserDialogs.Instance.HideLoading();

                   await UserDialogs.Instance.AlertAsync("Error","Houston we have a problem" , "Ok");
                }

                _oAuth2Service.OnSuccess -= onSuccessDelegate;
                _oAuth2Service.OnCancel -= onCancelDelegate;
                _oAuth2Service.OnError -= onErrorDelegate;
            };
            onErrorDelegate = (s, a) =>
            {
                _oAuth2Service.OnSuccess -= onSuccessDelegate;
                _oAuth2Service.OnCancel -= onCancelDelegate;
                _oAuth2Service.OnError -= onErrorDelegate;
                Debug.WriteLine($"ERROR: Instagram, MESSAGE: {a}");
            };
            onCancelDelegate = (s, a) =>
            {
                _oAuth2Service.OnSuccess -= onSuccessDelegate;
                _oAuth2Service.OnCancel -= onCancelDelegate;
                _oAuth2Service.OnError -= onErrorDelegate;
            };

            _oAuth2Service.OnSuccess += onSuccessDelegate;
            _oAuth2Service.OnCancel += onCancelDelegate;
            _oAuth2Service.OnError += onErrorDelegate;
            _oAuth2Service.Authenticate(InstagramClientId, InstagramScope, new Uri(InstagramAuthorizationUrl), new Uri(InstagramRedirectUrl));


        }

访问社交网络的服务。

public class OAuth2Service: IOAuth2Service
{
    public event EventHandler<string> OnSuccess = delegate { };
    public event EventHandler OnCancel = delegate { };
    public event EventHandler<string> OnError = delegate { };

    public void Authenticate(string clientId, string scope, Uri authorizeUrl, Uri redirectUrl)
    {
        var activity = CrossCurrentActivity.Current.Activity;

        DroidOAuth2Authenticator auth = new DroidOAuth2Authenticator(
            clientId: clientId,// your OAuth2 client id
            scope: scope, // the scopes for the particular API you're accessing, delimited by "+" symbols
            authorizeUrl: authorizeUrl, // the auth URL for the service
            redirectUrl: redirectUrl); // the redirect URL for the service



        auth.AllowCancel = true;
        auth.ShowErrors = true;

        EventHandler<AuthenticatorErrorEventArgs> errorDelegate = null;
        EventHandler<AuthenticatorCompletedEventArgs> completedDelegate = null;

        errorDelegate = (sender, eventArgs) =>
        {
            OnError?.Invoke(this, eventArgs.Message);

            auth.Error -= errorDelegate;
            auth.Completed -= completedDelegate;
        };

        completedDelegate = (sender, eventArgs) => {

            // UI presented, so it's up to us to dimiss it on Android
            // dismiss Activity with WebView or CustomTabs
            CrossCurrentActivity.Current.Activity.Finish();

            if (eventArgs.IsAuthenticated)
            {

                OnSuccess?.Invoke(this, eventArgs.Account.Properties["access_token"]);

            }
            else
            {
                // The user cancelled

                OnCancel?.Invoke(this, EventArgs.Empty);
            }
            auth.Error -= errorDelegate;
            auth.Completed -= completedDelegate;

        };

        auth.Error += errorDelegate;
        auth.Completed += completedDelegate;

        activity.StartActivity(auth.GetUI(activity));
    }

}