如何在初始登錄後自動登錄用戶？

Question

用戶登錄後，即使應用程序終止，我如何讓他們保持登錄狀態？目前用戶可以登錄，但當他們結束應用程序時，他們必須重新登錄。相反，即使應用程序結束，我也希望它們能夠登錄。下面是登錄用戶的代碼。

@IBAction func loginAction(sender: AnyObject) { 

    let username = self.usernameField.text 
    let password = self.passwordField.text 


    if(username!.utf16.count) < 4 || (password!.utf16.count < 5){ 

    let alert = UIAlertView(title: "Invalid", message: "Username must be greater then 4 and Password must be greater then 5", delegate: self, cancelButtonTitle: "OK") 
    alert.show() 

    }else{ 

     self.actInd.startAnimating() 

     PFUser.logInWithUsernameInBackground(username!, password: password!, block: { (user, error) -> Void in 

      self.actInd.stopAnimating() 

      if ((user) != nil) { 

       //var alert = UIAlertView(title: "Success", message: "Logged In", delegate: self, cancelButtonTitle: "OK") 
       //alert.show() 



       dispatch_async(dispatch_get_main_queue(),{ 

        self.performSegueWithIdentifier("login", sender: self) 


       }) 

      }else { 

       let alert = UIAlertView(title: "Error", message: "\(error)", delegate: self, cancelButtonTitle: "OK") 
       alert.show() 

      } 



     }) 

    } 


} 

Answer 1

你有沒有再次啓動應用後檢查PFUser.currentUser()？

實施例viewDidAppear：

let currentUser = PFUser.currentUser() 

if currentUser == nil { 
    // log in logic 

} else { 
    // user is logged in 

}