使用Facebook JavaScript Java SDK访问已登录的用户电子邮件

Question

I have tried using the javascritp sdk tutorial to make a login using facebook button, but I keep getting "undefined" in the email field, and the app doesn't request access to email..Any ideas what I should do differently? this is my code...

     <script>


 window.fbAsyncInit = function() {
    // init the FB JS SDK
    FB.init({
      appId      : '92',                        // App ID from the app dashboard
      channelUrl : '//om/fd/channel.php', // Channel file for x-domain comms
      status     : true,                                 // Check Facebook Login status
      cookie     : true,
      oauth:true,
      xfbml      : true                                  // Look for social plugins on the page
    });
  FB.Event.subscribe('auth.authResponseChange', function(response) {
      serverLogin();
    } else if (response.status === 'not_authorized') {
    FB.login(function(response){scope:'email'});
    } else {

FB.login(function(response){scope:'email'});
    }
  });
  };

  function serverLogin() {

    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me?fields=email,name', function(response) {
      console.log('Good to see you, ' + response.name + '.'+response.email);
      alert('Good to see you, ' + response.name + '.'+response.email);
    });
    //FB.logout();
  }
  // Load the SDK asynchronously

</script>
       <fb:login-button show-faces="false" width="100" max-rows="1"></fb:login-button>

name is returned correctly, but email is undefined....

Answer 1

在scope参数中定义权限，就像：

<fb:login-button show-faces="false" scope="email" width="100" max-rows="1"></fb:login-button>