问MVC4外部登录交换机帐户

EN

    [AllowAnonymous]
    public ActionResult ExternalLoginCallback(string returnUrl)
    {
        AuthenticationResult result = OAuthWebSecurity.VerifyAuthentication(Url.Action("ExternalLoginCallback", new { ReturnUrl = returnUrl }));
        if (!result.IsSuccessful)
        {
            return RedirectToAction("ExternalLoginFailure");
        }

        // Need to do fancy logic in case of multiple accounts

        if (User.Identity.IsAuthenticated)
        {
            // check for second blocking account
            // NOTE : This is not a real method, need a real solution
            var second = OAuthWebSecurity.GetUserIdFromProviderUserId(result.ProviderUserId);

            if (second != WebSecurity.CurrentUserId)
            {
                // redirect to failure
                // "This Login is used by another account... "
            }

   public ActionResult ExternalLoginCallback(string returnUrl)
    {
        AuthenticationResult result = OAuthWebSecurity.VerifyAuthentication(Url.Action("ExternalLoginCallback", new { ReturnUrl = returnUrl }));
        if (!result.IsSuccessful)
        {
            return RedirectToAction("ExternalLoginFailure");
        }


        // Need to do fancy logic in case of multiple accounts
        bool isBindingAction = User.Identity.IsAuthenticated;

        if (OAuthWebSecurity.Login(result.Provider, result.ProviderUserId, createPersistentCookie: false))
        {
            if (isBindingAction)
            {
                // tell the user that he has 2 accounts
                return RedirectToAction("ExternalLoginSwitch", new {provider = result.Provider});
            }
            return RedirectToLocal(returnUrl);
        }