尝试使用Facebook JS SDK从Facebook注销时,getLoginStatus返回状态未知

我有一个localhost网站,我使用Facebook C#SDK通过Facebook实现了登录.

启动配置类:

public class ExternalLoginConfig
{
    public void ConfigureAuth(IAppBuilder app)
    {
        app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);

        var facebookAuthenticationOptions = new FacebookAuthenticationOptions()
        {
            AppId = ConfigSettings.FacebookAppId,
            AppSecret = ConfigSettings.FacebookAppSecret,
            Scope = { "email" },
            Provider = new FacebookAuthenticationProvider()
            {
                OnAuthenticated = context =>
                {
                    var accessToken = context.AccessToken;
                    var facebookClient = new FacebookClient(accessToken);

                    var result = facebookClient.Get("me", new { fields = "email,first_name,last_name" }) as JsonObject;

                    string email = null;
                    string firstName = null;
                    string lastName = null;

                    if (result != null)
                    {
                        email = result.ContainsKey("email") ? (string) result["email"] : null;
                        firstName = result.ContainsKey("first_name") ? (string) result["first_name"] : null;
                        lastName = result.ContainsKey("last_name") ? (string) result["last_name"] : null;
                    }

                    if (firstName != null)
                    {
                        context.Identity.AddClaim(new Claim(ClaimTypes.GivenName, firstName));
                    }
                    if (lastName != null)
                    {
                        context.Identity.AddClaim(new Claim(ClaimTypes.Surname, lastName));
                    }
                    if (email != null)
                    {
                        context.Identity.AddClaim(new Claim(ClaimTypes.Email, email));
                    }

                    return Task.FromResult(0);
                },
                OnApplyRedirect = context =>
                {
                    context.Response.Redirect(context.RedirectUri + "&auth_type=reauthenticate");
                }
            }
        };
        app.UseFacebookAuthentication(facebookAuthenticationOptions);
    }
}

动作形式认证控制器:

[HttpPost]
[AllowAnonymous]
public virtual ActionResult Login(string provider, string returnUrl)
{
    ControllerContext.HttpContext.Session.RemoveAll();

    return new ExternalLoginResult(provider,
        Url.Action("LoginCallback", "Oauth", new { ReturnUrl = returnUrl }));
}

[AllowAnonymous]
public async Task LoginCallback(string returnUrl, string error)
{
    var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();

    if (loginInfo == null)
    {
        return Redirect(returnUrl);
    }

    User user = null;
    string userName = Guid.NewGuid().ToString();
    string firstName = loginInfo.ExternalIdentity.FindFirstValue(ClaimTypes.GivenName);
    string lastName = loginInfo.ExternalIdentity.FindFirstValue(ClaimTypes.Surname);
    string email = loginInfo.ExternalIdentity.FindFirstValue(ClaimTypes.Email);
    string externalProviderName = loginInfo.Login.LoginProvider;
    string externalProviderKey = loginInfo.Login.ProviderKey;

    var externalAuthenticationInfo = new ExternalAuthenticationInfo()
    {
        Username = userName,
        Email = email,
        FirstName = firstName,
        LastName = lastName,
        ExternalProviderName = externalProviderName,
        ExternalProviderKey = externalProviderKey
    };

    var loginResult = userProvider.ExternalLogin(externalProviderKey, email, out user);

    switch (loginResult)
    {
        case LoginResult.Success:
        {
            AuthenticationHelper.SetAuthenticatedUserId(user.ID);
            break;
        }
        case LoginResult.NotRegistered:
        {
            var registerResult = userProvider.Register(userName, email, null, externalAuthenticationInfo);

            if (registerResult.IsValid)
            {
                AuthenticationHelper.SetAuthenticatedUserId(registerResult.Result.ID);
            }

            break;
        }
    }

    return Redirect(returnUrl);
}

Facebook JS SDK初始化:

window.fbAsyncInit = function () {
    FB.init({
        appId: '@ConfigSettings.FacebookAppId',
        xfbml: true,
        version: 'v2.4'
    });
};

(function (d, s, id) {
    var js, fjs = d.getElementsByTagName(s)[0];
    if (d.getElementById(id)) { return; }
    js = d.createElement(s); js.id = id;
    js.src = "//connect.facebook.net/en_US/sdk.js";
    fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));

我试图用Facebook JS SDK将用户从Facebook登录,但是调用:

FB.getLoginStatus(function facebookLogoutCallback(facebookResponse) {
    if (facebookResponse.status !== 'connected') {
        return;
    }

    FB.logout(facebookLogoutCallback);
});

导致状态unknown而不是connected,在facebookResponse对象中返回.我也试图在FB.logout()没有if声明的情况下打电话,但它没有用.

也许你可以说,这种行为是由未经授权的用户状态引起的,但是在服务器端登录之后,用户实际上已登录:在我的网站和Facebook上也是如此.

似乎FB.logout函数中当前存在错误.在调用它之后,用户无法使用JS SDK再次登录此应用程序,因为FB.login函数返回
Object {status ="unknown",authResponse = null}

编辑:
发现在FB.logout()之后创建了一个名为"fblo_*"的cookie,这似乎就是这个原因.我不能确切地说它为什么存在以及它做了什么,但删除它会使登录再次起作用.

因此,我创建了一个小脚本来查找此cookie并在我调用FB.login()之前将其删除,您可能希望在单击事件中调用它(https://developers.facebook.com/docs/reference/javascript/ FB.login/v2.5).

function delete_cookie(name) 
{
    document.cookie = name + '=; expires=Thu, 01 Jan 1970 00:00:01 GMT; path=/';
}


var cookies = document.cookie.split(";");
for (var i = 0; i < cookies.length; i++)
{
    if(cookies[i].split("=")[0].indexOf("fblo_") != -1)
        delete_cookie(cookies[i].split("=")[0]);
}