facebook - 检索电子邮件 FacebookSDK 和 Swift

Question

我在我的应用程序中成功实现了 facebook 登录，但我无法查询/检索用户的电子邮件地址。

我有以下代码:

import UIKit

class testViewController: UIViewController, FBSDKLoginButtonDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        if (FBSDKAccessToken.currentAccessToken() != nil)
        {
            // User is already logged in, do work such as go to next view controller.

            // Or Show Logout Button
            let loginView : FBSDKLoginButton = FBSDKLoginButton()
            self.view.addSubview(loginView)
            loginView.center = self.view.center
            loginView.readPermissions = ["public_profile", "email", "user_friends"]
            loginView.delegate = self
            self.returnUserData()
        }
        else
        {
            let loginView : FBSDKLoginButton = FBSDKLoginButton()
            self.view.addSubview(loginView)
            loginView.center = self.view.center
            loginView.readPermissions = ["public_profile", "email", "user_friends"]
            loginView.delegate = self
        }

    }

    // Facebook Delegate Methods

    func loginButton(loginButton: FBSDKLoginButton!, didCompleteWithResult result: FBSDKLoginManagerLoginResult!, error: NSError!) {
        println("User Logged In")

        if ((error) != nil)
        {
            // Process error
        }
        else if result.isCancelled {
            // Handle cancellations
        }
        else {
            // If you ask for multiple permissions at once, you
            // should check if specific permissions missing
            if result.grantedPermissions.contains("email")
            {
                // Do work
            }

            self.returnUserData()
        }

    }

    func loginButtonDidLogOut(loginButton: FBSDKLoginButton!) {
        println("User Logged Out")
    }

    func returnUserData() {
        let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: nil)
        graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in

            if ((error) != nil)
            {
                // Process error
                println("Error: \(error)")
            }
            else
            {
                println("fetched user: \(result)")
                let userName : NSString = result.valueForKey("name") as! NSString
                println("User Name is: \(userName)")
                let userEmail : NSString = result.valueForKey("email") as! NSString
                println("User Email is: \(userEmail)")
            }
        })
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

以及 println 输出:

fetched user: {
    id = 808101565906152;
    name = "Marcelo Pontes Machado";
}

当我尝试显示电子邮件时，我得到了一个空值。

我认为代码是正确的，也许是我错过导入的一些 SDK？

Answer 1

将你想要从 Graph 请求中返回的字段放入你的参数中

FBSDKGraphRequest(graphPath: "me", parameters: ["fields":"id,email,name,picture.width(480).height(480)"]).startWithCompletionHandler({

因为 Graph API 有时可能只返回最少量的信息，除非另有要求。