ios - 使用 Swift 在 IOS 上的 Twitter 单点登录

Question

我正在我的应用程序中实现 Twitter 登录。我可以使用 Fabric 登录，一切似乎都很好。现在我希望用户只登录一次，下次他/她打开应用程序时，应该显示一条消息“您已经登录”或类似的内容，登录按钮不应该出现在屏幕上。当用户第二次启动应用程序时，我还应该能够获取用户信息(Twitter 用户名)，我该如何实现？
到目前为止，这是我的代码

import UIKit
import TwitterKit


class ViewController: UIViewController {

override func viewDidLoad() {

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


}
override func viewDidAppear(animated: Bool) {

    var logInButton = TWTRLogInButton { (session, error) in
        if let unwrappedSession = session {

            print(session?.userName)
            print(session?.userID)


            //requesting Email address
            let client = TWTRAPIClient.clientWithCurrentUser()
            let request = client.URLRequestWithMethod("GET",
                URL: "https://api.twitter.com/1.1/account/verify_credentials.json",
                parameters: ["include_email": "true", "skip_status": "true"],
                error: nil)

            client.sendTwitterRequest(request) { response, data, connectionError in
                print(data)
                print(response)

            }

            let alert = UIAlertController(title: "Logged In",
                message: "User \(unwrappedSession.userName) has logged in",
                preferredStyle: UIAlertControllerStyle.Alert
            )
            alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
            self.presentViewController(alert, animated: true, completion: nil)
        } else {
            print("Login error:  \(error!.localizedDescription)");
        }

    }

    logInButton.loginMethods = [.SystemAccounts]

    // TODO: Change where the log in button is positioned in your view
    logInButton.center = self.view.center
    self.view.addSubview(logInButton)

    let store = Twitter.sharedInstance().sessionStore
    if let userID = store.session()?.userID {
        //store.logOutUserID(userID)
    }

}
}

Answer 1

你可以使用下面对我有用的代码

if((Twitter.sharedInstance().sessionStore.session()?.userID) == nil)
 {
//show twitter login button
 }
else
 {
//user has already logged in take appropriate action
}

希望对您有所帮助:)