在默认MVC5应用程序中的帐户关联步骤中从外部提供商Google和Facebook获取电子邮件

您需要显式配置FacebookAuthenticationOptions以从经过身份验证的用户获取电子邮件地址.

在MVC5项目中,在Startup.Auth.cs中添加这些行

        var options = new FacebookAuthenticationOptions() {
            AppId = "xxxxxxxx",
            AppSecret = "xxxxxxxxx"
        };
        options.Scope.Add("email");
        app.UseFacebookAuthentication(options);

更新 将我的示例代码减少到绝对最小值.你的更新代码顺便说一下,我也试过Facebook和谷歌.

请在本帖子的底部看到更新!

以下适合我的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;

而对于谷歌:

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;

如果我在这里设置断点:

var email = emailClaim.Value;

我在调试器中看到了Facebook和Google的电子邮件地址.

更新1:旧答案让我感到困惑所以我用自己项目中的代码更新了它,我刚刚调试过,我知道有效.

更新2:使用新的ASP.NET Identity 2.0 RTM版本,您不再需要本文中的任何代码.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 });
    }
}