我正在尝试从Facebook获取用户名和用户电子邮件.我阅读了很多关于这个主题的信息,这是我的最终代码,仅在我的facebook app管理员帐户上有效：
public partial class Startup
{
public void ConfigureAuth(IAppBuilder app)
{
/*Other external login options*/
var FacebookOptions = new FacebookAuthenticationOptions()
{
AppId = "My App Id",AppSecret = "My App Secret",SignInAsAuthenticationType = DefaultAuthenticationTypes.ExternalCookie,BackchannelHttpHandler = new FacebookBackChannelHandler(),UserInformationEndpoint = "https://graph.facebook.com/v2.7/me?fields=id,name,email"
};
}
}
public class FacebookBackChannelHandler : HttpClientHandler
{
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,System.Threading.CancellationToken cancellationToken)
{
if (!request.RequestUri.AbsolutePath.Contains("/oauth"))
{
request.RequestUri = new Uri(request.RequestUri.AbsoluteUri.Replace("?access_token","&access_token"));
}
return await base.SendAsync(request,cancellationToken);
}
}
public class AccountController : Controller
{
public async Task<ActionResult> ExternalLoginCallback(string returnUrl)
{
var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();
/*my sign in code that works on my facebook app admin account*/
}
}
在每个帐号我得到loginInfo.Email等于null.
当有人点击“使用Facebook登录”时,他会收到以下消息：
如果我点击“查看您提供的信息”,我会得到：
我错过了什么？为什么不起作用？
解决方法
终于找到了答案！所有需要做的就是将Scope = {“email”}添加到FacebookOptions,这就解决了这个问题！
我的代码现在：
public partial class Startup
{
public void ConfigureAuth(IAppBuilder app)
{
/*Other external login options*/
var FacebookOptions = new FacebookAuthenticationOptions()
{
AppId = "My App Id",Scope = { "email" },email"
};
}
}
其余代码保持不变.如果此问题返回,我只为案例添加了错误页面：
public class AccountController : Controller
{
public async Task<ActionResult> ExternalLoginCallback(string returnUrl)
{
var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();
if(loginInfo.Email == null)
{
return RedirectToAction("FacebookError","Account");
}
/*my sign in code*/
}
}
