swift - 登录警报 swift 2.0 后打开一个新的 View Controller

Question

如果登录成功，我正在尝试更改 View Controller ，但我不确定如何执行此操作。到目前为止，这是我尝试过的。提前致谢!

@IBAction func signinaction(sender: AnyObject) {
    let user = self.usernamefield.text!

    ref.authUser(emailfield.text, password: passwordfield.text, withCompletionBlock: { error, authData in

        if error != nil
        {
            let alert = UIAlertController(title: "Error", message: "Enter Email and Password.", preferredStyle: UIAlertControllerStyle.Alert)
            let action = UIAlertAction(title: "Ok", style: .Default, handler: nil)
            alert.addAction(action)
            self.presentViewController(alert, animated: true, completion: nil)
            print("can not sign in")
        }
        else
        {

            let storyboard = UIStoryboard(name: "Main", bundle: nil);
            let viewName:NSString = "NewView"
            let vc = storyboard.instantiateViewControllerWithIdentifier(viewName as String) as! HomeViewController
            let uid = authData.uid
            print("Success with user: \(uid)")
            let alert = UIAlertController(title: "Success", message: "Welcome \(user)", preferredStyle: UIAlertControllerStyle.Alert)
            let action = UIAlertAction(title: "Ok", style: .Default, handler: nil)
            alert.addAction(action)
            self.navigationController?.pushViewController(vc as HomeViewController, animated: true)

        }

    })
}

Answer 1

假设所有这些都包含在导航 Controller 中的 View Controller ，那么您所拥有的应该可以正常工作。但是请注意，您正在创建一个永远不会显示的警报。我的猜测是您想显示成功警报，然后打开新的 View Controller ，例如:

            let alert = UIAlertController(title: "Success", message: "Welcome \(user)", preferredStyle: UIAlertControllerStyle.Alert)
            let action = UIAlertAction(title: "Ok", style: .Default) { _ in
                self.navigationController?.pushViewController(vc, animated: true)
            }
            alert.addAction(action)

            self.presentViewController(alert, animated: true, completion: nil)

如果这仍然不起作用，我会确保当前 View Controller 实际显示在导航 Controller 中。