ios - 如何使用解析保持当前用户 session 处于事件状态？

Question

我试图让当前用户 session 保持事件状态，直到用户决定注销。我应该实现什么代码？究竟应该在哪里实现？ Root View 的 viewDidLoad 或 viewWillAppear 函数？我尝试在我的 Root View 中使用此代码:

override func viewDidAppear(animated: Bool) {
        let vc = ViewController()
        var loggedIn = false

        if PFUser.currentUser() != nil {
            loggedIn = true
        } else {
            presentViewController(vc, animated: true, completion: nil)
        }
    }

但是每当我停止模拟器并再次运行它时，我都必须重新登录。什么是最好的解决方案？保留在我的“ViewController”中是我的主视图，其中包含我的登录/注册字段。所以我基本上想要一种方法来说明当前用户 session 是否存在，继续，否则，显示初始 View 。

Answer 1

在您的应用委托(delegate)中试试这个...

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

...

PFUser *currentUser = [PFUser currentUser];

if (currentUser) {
  // there is a user logged in go to the main screen
    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];
    MainViewController *mainViewController = (MainViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:@"Main"];

    //set the root controller to it
    self.window.rootViewController = mainViewController;
} else {
// Log in!
    UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Login" bundle: nil];
    LoginViewController *loginViewController = (LoginViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:@"Login"];

    //set the root controller to it
    self.window.rootViewController = loginViewController;
}

...