asp.net-mvc-5 – 在默认的MVC5应用程序的帐户关联步骤中,从外部提供商Google和Facebook获取电子邮件

显然，您可以通过向Startup.Auth.cs中的FacebookAuthenticationoptions对象添加范围来通过Facebook提供者执行此操作：

http://blogs.msdn.com/b/webdev/archive/2013/10/16/get-more-information-from-social-providers-used-in-the-vs-2013-project-templates.aspx

List<string> scope = new List<string>() { "email" };
var x = new FacebookAuthenticationoptions();
x.Scope.Add("email");
...
app.UseFacebookAuthentication(x);

如何与Google提供商一样？ GoogleAuthenticationoptions类/对象没有x.Scope属性！

解决方法

请在本帖子的底部看到更新！

以下适用于我的Facebook：

StartupAuth.cs：

var facebookAuthenticationoptions = new FacebookAuthenticationoptions()
{
    AppId = "x",AppSecret = "y"
};
facebookAuthenticationoptions.Scope.Add("email");
app.UseFacebookAuthentication(facebookAuthenticationoptions);

ExternalLoginCallback方法：

var externalIdentity = HttpContext.GetowinContext().Authentication.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);
var emailClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Email);
var email = emailClaim.Value;

而对于Google：

StartupAuth.cs

app.UseGoogleAuthentication();

ExternalLoginCallback方法(与Facebook相同)：

var externalIdentity = HttpContext.GetowinContext().Authentication.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);
var emailClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Email);
var email = emailClaim.Value;

如果我在这里设置一个断点：

var email = emailClaim.Value;

我在调试器中看到Facebook和Google的电子邮件地址。

更新1：旧的答案让我困惑，所以我更新了我在我自己的项目中的代码，我刚刚调试，我知道工作。

更新2：使用新的ASP.NET Identity 2.0 RTM版本，您不再需要此帖中的任何代码。获取电子邮件的正确方法是简单地执行以下操作：

> Startup.Auth.cs

app.UseFacebookAuthentication(
       appId: "x",appSecret: "y");

    app.UseGoogleAuthentication();

> AccountController.cs

//
// GET: /Account/ExternalLoginCallback
[AllowAnonymous]
public async Task<ActionResult> ExternalLoginCallback(string returnUrl)
{
    var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();
    if (loginInfo == null)
    {
        return RedirectToAction("Login");
    }

    // Sign in the user with this external login provider if the user already has a login
    var result = await SignInHelper.ExternalSignIn(loginInfo,isPersistent: false);
    switch (result)
    {
        case SignInStatus.Success:
            return RedirectToLocal(returnUrl);
        case SignInStatus.LockedOut:
            return View("Lockout");
        case SignInStatus.RequiresTwoFactorAuthentication:
            return RedirectToAction("SendCode",new { ReturnUrl = returnUrl });
        case SignInStatus.Failure:
        default:
            // If the user does not have an account,then prompt the user to create an account
            ViewBag.ReturnUrl = returnUrl;
            ViewBag.LoginProvider = loginInfo.Login.LoginProvider;
            return View("ExternalLoginConfirmation",new ExternalLoginConfirmationviewmodel { Email = loginInfo.Email });
    }
}