Asp.net 5 MVC 6，添加facebook邮箱权限

Question

我想知道如何为 Facebook 外部登录添加更多权限，特别是电子邮件。外部登录工作正常，但我似乎无法将用于 MVC 5 的相同代码复制到这个代码中，所以这就是我现在所拥有的：

        services.Configure<FacebookAuthenticationOptions>(options =>
        {
            options.AppId = Configuration["Authentication:Facebook:AppId"];
            options.AppSecret = Configuration["Authentication:Facebook:AppSecret"];
            options.Scope.Add("email");

        });

但是没有添加邮箱权限。

这是我在 MVC 5 中与 Facebook SDK 块一起使用的代码：

app.UseFacebookAuthentication(new FacebookAuthenticationOptions
        {
            AppId = "XXXXXX",
            AppSecret = "XXXXXXX",
            Scope = { "email" },
            Provider = new FacebookAuthenticationProvider
            {
                OnAuthenticated = async context =>
                {
                     context.Identity.AddClaim(new System.Security.Claims.Claim("FacebookAccessToken", context.AccessToken));
                }
            }
        });

Answer 1

好的，感谢@Mike Wasson 的评论，它让我找到了一个可行的答案，

这个SO post

所以我在启动时所做的更改 class 是这样的：

        services.Configure<FacebookAuthenticationOptions>(options =>
        {
            options.AppId = Configuration["Authentication:Facebook:AppId"];
            options.AppSecret = Configuration["Authentication:Facebook:AppSecret"];
            options.Scope.Add("email");
            options.BackchannelHttpHandler = new FacebookBackChannelHandler();
            options.UserInformationEndpoint = "https://graph.facebook.com/v2.4/me?fields=id,name,email,first_name,last_name,location";
        }

并添加了这个新的 class

public class FacebookBackChannelHandler : HttpClientHandler
{
    protected override async System.Threading.Tasks.Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
    {
        // Replace the RequestUri so it's not malformed
        if (!request.RequestUri.AbsolutePath.Contains("/oauth"))
        {
            request.RequestUri = new Uri(request.RequestUri.AbsoluteUri.Replace("?access_token", "&access_token"));
        }

        return await base.SendAsync(request, cancellationToken);
    }
}

并且不需要进一步调整，它现在可以检索电子邮件:D

Answer 2

Aspnet 核心 RC2

 app.UseFacebookAuthentication(options =>
        {                
            options.AppId = Configuration["Authentication:Facebook:AppId"];
            options.AppSecret = Configuration["Authentication:Facebook:AppSecret"];                
            options.Fields.Add("name");
            options.Fields.Add("email");                
            options.Events = new OAuthEvents
            {
                OnRemoteFailure = context =>
                {
                    context.Response.Redirect($"/Account/ExternalLoginCallback?remoteError={ UrlEncoder.Default.Encode(context.Failure.Message) }");
                    context.HandleResponse();
                    return Task.FromResult(0);
                }
            };
        });