用户电子邮件没有通过Facebook登录

Question

回到我试图通过一个的Facebook登录页面访问用户的信息在我的WinForm应用。即使我要求用户在email扩展权限，我得到后提交的名称和编号。

public partial class Form1 : Form 
{ 
    private const string AppId = "MY_APP_ID_IS_HERE"; 
    private Uri loginUrl; 
    private const string extendedPermissions = "public_profile,user_friends,email"; 
    FacebookClient fbClient = new FacebookClient(); 
    private string _accessToken; 
    private bool _authorized; 
    private string _currentName; 
    private string _currentEmail; 
    public Form1() 
    { 
     InitializeComponent(); 
    } 

    private void Form1_Load(object sender, EventArgs e) 
    { 
     Login(); 
    } 

    private void Login() 
    { 
     dynamic parameters = new ExpandoObject(); 
     parameters.client_id = AppId; 
     parameters.redirect_uri = "https://www.facebook.com/connect/login_success.html"; 
     parameters.response_type = "token"; 
     parameters.display = "popup"; 
     if (!string.IsNullOrWhiteSpace(extendedPermissions)) 
      parameters.scope = extendedPermissions; 
     var fb = new FacebookClient(); 
     loginUrl = fb.GetLoginUrl(parameters); 
     webBrowser1.Navigate(loginUrl.AbsoluteUri); 
    } 

    private void webBrowser1_Navigated(object sender, WebBrowserNavigatedEventArgs e) 
    { 
     if (webBrowser1.Visible) 
     { 
      var fb = new FacebookClient(); 
      FacebookOAuthResult oauthResult; 
      if (fb.TryParseOAuthCallbackUrl(e.Url, out oauthResult)) 
      { 
       if (oauthResult.IsSuccess) 
       { 
        _accessToken = oauthResult.AccessToken; 
        _authorized = true; 
       } 
       else 
       { 
        _accessToken = ""; 
        _authorized = false; 
       } 
       if (_authorized) 
       { 
        fb = new FacebookClient(_accessToken); 
        dynamic result = fb.Get("me"); 
        _currentName = result.name; 
        _currentEmail = result.email; 
        lblLoggedInUser.Text = string.Format("Facebook User: {0}", _currentName); 
        lblPassword.Text = string.Format("Email: {0}", _currentEmail); 
        //Do what need being done now that we are logged in! 
       } 
       else 
       { 
        MessageBox.Show("Couldn't log into Facebook!", "Login unsuccessful", MessageBoxButtons.OK, 
            MessageBoxIcon.Error); 
       } 
      } 
     } 
    } 

} 

当我运行查询，并要求使用Facebook的图形API浏览器用户的电子邮件，它返回调试消息：

显然，我的程序不要求使用用户的电子邮件的权限。因为在我提交我的登录信息后立即显示带有“成功”文本的白页，并且没有返回任何电子邮件值。

我怎样才能改变我的登录页面，要求用户的电子邮件？

Answer 1

尝试

dynamic result = fb.Get("me?fields=id,name,email");