我注意到2017年3月27日Facebook GRAPH API到期后，我的Facebook应用程序无法访问我的网络应用程序。
主要是OAuthWebSecurity无法从facebook图API获取登录状态，我已经浏览了开发人员组中的bug报告。但他们没有提供解决方案。我在link中为NopCommerce提供了一个解决方案。但是我没有为MVC 4获得任何完美的解决方案。
我已经完成了这个link，他们在MVC 5中找到了系统但是我需要MVC4中的解决方案并提到OWIN不支持MVC4在VS 2012中
那么我该如何解决这个问题呢。自从过去一周以来，我一直在经历这个问题。
主要是在这段代码中发生异常
AuthenticationResult result = OAuthWebSecurity.VerifyAuthentication(Url.Action("ExternalLoginCallback", new { ReturnUrl = returnUrl }));
它将IsSuccessful作为false返回，其余参数也为null。
我研究过Facebook已经将API string的返回类型更改为JSON所以如何开发我的代码以准确地获取JSON。谢谢。
更新 这个问题仍然没有答案。任何人都可以帮助我。
答案 0 :(得分：5)
你检查过这个解决方案吗？
“我们在2017年3月27日星期一遇到了同样的问题，当时Facebook停止支持他们的Graph API v2.2。 我们也使用DotNetOpenAuth，它最初是通过Nuget安装的。源代码可在“
下面的链接中找到编辑（2017年4月18日）： 您好，我今天早上遇到了以下链接，它解决了我的问题。试试看，让我知道:)。
https://github.com/DotNetOpenAuth/DotNetOpenAuth/issues/397
代码由用户'adoconnection'提供。这是链接中的第4个帖子。
我把头发拉过来。洛尔
祝你好运！
答案 1 :(得分：1)
根据Previous Answer，我得给你一个解决方案。在MVC4，每个人都写下他们的AppID和SecurityCode。由于facebook GRAPH API的更改，以前的链接被破坏了。因此，每个人都需要更改RegisterFacebookClient calss。但是这个类是.Net库中的密封类，所以任何人都无法扩展或覆盖它。因此，我们需要使用wrapper类。让我们考虑我的Wrapper类是FacebookClientV2Dot3，因此我的课程将是
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;
using DotNetOpenAuth.AspNet.Clients;
using Newtonsoft.Json;
public class FacebookClientV2Dot3 : OAuth2Client
{
#region Constants and Fields
/// <summary>
/// The authorization endpoint.
/// </summary>
private const string AuthorizationEndpoint = "https://www.facebook.com/dialog/oauth";
/// <summary>
/// The token endpoint.
/// </summary>
private const string TokenEndpoint = "https://graph.facebook.com/oauth/access_token";
/// <summary>
/// The user info endpoint.
/// </summary>
private const string UserInfoEndpoint = "https://graph.facebook.com/me";
/// <summary>
/// The app id.
/// </summary>
private readonly string _appId;
/// <summary>
/// The app secret.
/// </summary>
private readonly string _appSecret;
/// <summary>
/// The requested scopes.
/// </summary>
private readonly string[] _requestedScopes;
#endregion
/// <summary>
/// Creates a new Facebook OAuth2 client, requesting the default "email" scope.
/// </summary>
/// <param name="appId">The Facebook App Id</param>
/// <param name="appSecret">The Facebook App Secret</param>
public FacebookClient(string appId, string appSecret)
: this(appId, appSecret, new[] { "email" }) { }
/// <summary>
/// Creates a new Facebook OAuth2 client.
/// </summary>
/// <param name="appId">The Facebook App Id</param>
/// <param name="appSecret">The Facebook App Secret</param>
/// <param name="requestedScopes">One or more requested scopes, passed without the base URI.</param>
public FacebookClient(string appId, string appSecret, params string[] requestedScopes)
: base("facebook")
{
if (string.IsNullOrWhiteSpace(appId))
throw new ArgumentNullException("appId");
if (string.IsNullOrWhiteSpace(appSecret))
throw new ArgumentNullException("appSecret");
if (requestedScopes == null)
throw new ArgumentNullException("requestedScopes");
if (requestedScopes.Length == 0)
throw new ArgumentException("One or more scopes must be requested.", "requestedScopes");
_appId = appId;
_appSecret = appSecret;
_requestedScopes = requestedScopes;
}
protected override Uri GetServiceLoginUrl(Uri returnUrl)
{
var state = string.IsNullOrEmpty(returnUrl.Query) ? string.Empty : returnUrl.Query.Substring(1);
return BuildUri(AuthorizationEndpoint, new NameValueCollection
{
{ "client_id", _appId },
{ "scope", string.Join(" ", _requestedScopes) },
{ "redirect_uri", returnUrl.GetLeftPart(UriPartial.Path) },
{ "state", state },
});
}
protected override IDictionary<string, string> GetUserData(string accessToken)
{
var uri = BuildUri(UserInfoEndpoint, new NameValueCollection { { "access_token", accessToken } });
var webRequest = (HttpWebRequest)WebRequest.Create(uri);
using (var webResponse = webRequest.GetResponse())
using (var stream = webResponse.GetResponseStream())
{
if (stream == null)
return null;
using (var textReader = new StreamReader(stream))
{
var json = textReader.ReadToEnd();
var extraData = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
var data = extraData.ToDictionary(x => x.Key, x => x.Value.ToString());
data.Add("picture", string.Format("https://graph.facebook.com/{0}/picture", data["id"]));
return data;
}
}
}
protected override string QueryAccessToken(Uri returnUrl, string authorizationCode)
{
var uri = BuildUri(TokenEndpoint, new NameValueCollection
{
{ "code", authorizationCode },
{ "client_id", _appId },
{ "client_secret", _appSecret },
{ "redirect_uri", returnUrl.GetLeftPart(UriPartial.Path) },
});
var webRequest = (HttpWebRequest)WebRequest.Create(uri);
string accessToken = null;
HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
// handle response from FB
// this will not be a url with params like the first request to get the 'code'
Encoding rEncoding = Encoding.GetEncoding(response.CharacterSet);
using (StreamReader sr = new StreamReader(response.GetResponseStream(), rEncoding))
{
var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
var jsonObject = serializer.DeserializeObject(sr.ReadToEnd());
var jConvert = JsonConvert.DeserializeObject(JsonConvert.SerializeObject(jsonObject));
Dictionary<string, object> desirializedJsonObject = JsonConvert.DeserializeObject<Dictionary<string, object>>(jConvert.ToString());
accessToken = desirializedJsonObject["access_token"].ToString();
}
return accessToken;
}
private static Uri BuildUri(string baseUri, NameValueCollection queryParameters)
{
var keyValuePairs = queryParameters.AllKeys.Select(k => HttpUtility.UrlEncode(k) + "=" + HttpUtility.UrlEncode(queryParameters[k]));
var qs = String.Join("&", keyValuePairs);
var builder = new UriBuilder(baseUri) { Query = qs };
return builder.Uri;
}
/// <summary>
/// Facebook works best when return data be packed into a "state" parameter.
/// This should be called before verifying the request, so that the url is rewritten to support this.
/// </summary>
public static void RewriteRequest()
{
var ctx = HttpContext.Current;
var stateString = HttpUtility.UrlDecode(ctx.Request.QueryString["state"]);
if (stateString == null || !stateString.Contains("__provider__=facebook"))
return;
var q = HttpUtility.ParseQueryString(stateString);
q.Add(ctx.Request.QueryString);
q.Remove("state");
ctx.RewritePath(ctx.Request.Path + "?" + q);
}
}
在这里查看我已用新版本链接替换所有API链接。
现在您需要修改
AuthConfig
只需使用包装类
OAuthWebSecurity.RegisterClient(new FacebookClientV2Dot3("AppID", "HassedPassword"));
然后一切顺利。你的Facebook登录将恢复到以前的状态。
但是，您可能会遇到有关此新API的新问题，而不是以前的API，问题是IP Whitelisting。像这样image。希望你除此之外什么都不需要。快乐的编码。