Swift programmatically navigate to another view co

问题:

I'm using following code to programmatically navigate to another ViewController. It works fine, but it some how hides the navigation bar. How do I fix this? (the navigation bar is created by embeding the ViewController in the navigation controller if that matters.)

let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)

let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("nextView") as NextViewController
self.presentViewController(nextViewController, animated:true, completion:nil)

回答1:

In Swift 3

With a programmatically created Controller

If you want to navigate to Controller created Programmatically, then do this:

let newViewController = NewViewController()
self.navigationController?.pushViewController(newViewController, animated: true)

With a StoryBoard created Controller

If you want to navigate to Controller on StoryBoard with Identifier "newViewController", then do this:

let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "newViewController") as! NewViewController
        self.present(newViewController, animated: true, completion: nil)

回答2:

You should push the new viewcontroller by using current navigation controller, not present.

self.navigationController.pushViewController(nextViewController, animated: true)

回答3:

SWIFT 4.x

The Strings in double quotes always confuse me, so I think answer to this question needs some graphical presentation to clear this out.

For a banking app, I have a LoginViewController and a BalanceViewController. Each have their respective screens.

The app starts and shows the Login screen. When login is successful, app opens the Balance screen.

Here is how it looks:

The login success is handled like this:

let storyBoard: UIStoryboard = UIStoryboard(name: "Balance", bundle: nil)
let balanceViewController = storyBoard.instantiateViewController(withIdentifier: "balance") as! BalanceViewController
self.present(balanceViewController, animated: true, completion: nil)

As you can see, the storyboard ID 'balance' in small letters is what goes in the second line of the code, and this is the ID which is defined in the storyboard settings, as in the attached screenshot.

The term 'Balance' with capital 'B' is the name of the storyboard file, which is used in the first line of the code.

We know that using hard coded Strings in code is a very bad practice, but somehow in iOS development it has become a common practice, and Xcode doesn't even warn about them.

回答4:

So If you present a view controller it will not show in navigation controller. It will just take complete screen. For this case you have to create another navigation controller and add your nextViewController as root for this and present this new navigationController.

Another way is to just push the view controller.

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

For more info check Apple documentation:- https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIViewController_Class/#//apple_ref/doc/uid/TP40006926-CH3-SW96

回答5:

According to @jaiswal Rajan in his answer. You can do a pushViewController like this:

let storyBoard: UIStoryboard = UIStoryboard(name: "NewBotStoryboard", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "NewViewController") as! NewViewController
self.navigationController?.pushViewController(newViewController, animated: true)

回答6:

OperationQueue.main.addOperation {
   let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
   let newViewController = storyBoard.instantiateViewController(withIdentifier: "Storyboard ID") as! NewViewController
   self.present(newViewController, animated: true, completion: nil)
}

It worked for me when I put the code inside of the OperationQueue.main.addOperation, that will execute in the main thread for me.