I am familiar with this code: self.navigationItem.leftBarButtonItem = self.editButtonItem.
See this code:
class ThirdViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet var tblTasks: UITableView! // declaring this allows you to reload the tableView to update your items
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
I have the code that allows for the edit button to be present, yet no edit button is to be seen in my app nor the storyboard.
I am a Swift beginner, if someone could point me in the right direction that would be awesome.
The stock "Edit" button is only available on UITableViewController. For other view controller types you'll have to create a button yourself.
If you add it into navigationItem you should embed that view controller into UINavigationController to see that button.
You will not see that button in Storyboard because you set it in code. In Storyboard you setup only initial state of the controller.
How to setup editing mode in UIViewController subclass:
There is editButtonItem variable in UIViewController. If you add it on screen, setEditing(_:,animated:) will be triggered when user tap that button.
Also it will change button text between Edit and Done according to ViewController's isEditing state.
You can get current state from self.isEditing
Do not forget to call super.setEditing(_:animated:), or it will not change state of the button and view controller.
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.rightBarButtonItem = self.editButtonItem
}
override func setEditing(_ editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
// custom code to handle edit mode
}
editButtonItem (iOS 10.0+)
isEditing (iOS 2.0+)
setEditing(_:animated:) (iOS 2.0+)
You can create your own edit button, like:
self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Edit", style: .Plain, target: self, action: Selector("editTableView"))
And then:
func editTableView()
{
if self.navigationItem.rightBarButtonItem.title == "Edit"
{
self.navigationItem.rightBarButtonItem.title = "Done"
//edit your tableView Here!
}
else
{
self.navigationItem.rightBarButtonItem.title = "Edit"
//when youre finishing editing
}
}
Related
I have a view controller where I need to add a custom back button. So I have added a custom backButtonItem. But After adding custom back button the default behavior of my view controller to go back by swipe stops working as expected.
If I remove the custom back button from the view controller, the behavior of view controller is as expected but as soon as I add custom back button the default behavior stops.
I have added the custom back button like this
self.navigationItem.leftBarButtonItem = getCustomBackBarButtonItem(viewController: self)
I have tried to use backBarButtonItem instead of leftBarButtonItem, but by doing that the custom back button doesn't appear and the view controller's behavior is as expected.
If I remove the above code the behavior of the view controller is as expected and it smoothly goes back by swipe.
Be sure to build the UIBarButtonItem doing something like this:
let customBack = UIBarButtonItem(title: "Back", style:.done, target:self, action: #selector(self.letsGoBack))
and then implement the pop back function with:
#objc func letsGoBack() {
self.navigationController?.popViewController(animated: true)
}
so at the end it's just:
self.navigationItem.leftBarButtonItem = customBack
if you want to keep the swipe back gesture, you might subclass your navigation controller doing so:
class YourNavigationController: UINavigationController, UIGestureRecognizerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.interactivePopGestureRecognizer?.delegate = self
}
public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return self.viewControllers.count > 1
}
}
Instead of setting delegate to self you can simply add this line:
self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
So it won't go to any of interactive PopGestureRecognizer's delegate method and the navigation Controller behavior will be as per your expectation. This is the small workaround to achieve the expected behavior.
To navigate back to previous viewController
Initialize UIBarButton
var backBtn:UIBarButtonItem!
add UIBarButton to NavigationBar
backBtn = UIBarButtonItem(title: "Go-Back" , style: .plain, target: self, action: #selector(self.backBtnClicked(_:)))
self.navigationItem.leftBarButtonItem = backBtn
add this function into your class
func backBtnClicked(_ sender:UIBarButtonItem) {
if let redirect = self.navigationController?.popViewController(animated: true) {
// If you open this viewController by using pushViewController this will called
} else {
self.dismiss(animated: true, completion: nil)
// If you open this viewController by using present this will called
}
}
Hope this will help you
I followed this tutorial to smoothly hide the statusBar smoothly hide statusBar and everything works fine when I use it on practice projects. I use the code in other project's that do not have SplitVC but have a tabBar and uses a navVC & tableView and everything works fine. In those I can successfully make it appear/disappear.
In my actual project I'm using a SplitViewController for iPad. I noticed when I implemented the directions from the link to my SplitViewController the statusBar wouldn't hide. I then made a new project using Apple's default MasterDetailApp to make sure I wasn't doing anything wrong but it doesn't work there either. I kept all of Apple's original code and only added in the necessary methods to make the statusBar appear/disappear
in info.plist I added the View controller-based status bar appearance and set it to YES
in storyboard I added a purple button to the DetailVC to trigger the statusBar disappearance. I also added in the method to make the backBar button disappear/reappear
I added all the methods to make the statusBar disappear/disappear to the DetailVC scene.
I added a tapGesture to the scene to make the statusBar and backButton reappear
I clicked the Plus button on the Master scene, a date appeared, clicked it to get to the DetailVC, pressed the purple buttonPressed to hide the statusBar and backButton but only the backButton gets hidden. I touch the background and the backButton reappears. The statusBar doesn't move.
I kept all the original code from Apple's project's and added mines below it:
class DetailViewController: UIViewController {
//MARK:- Apple's code
#IBOutlet weak var detailDescriptionLabel: UILabel!
func configureView() {
if let detail = detailItem {
if let label = detailDescriptionLabel {
label.text = detail.description
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
configureView()
// make backButton and statusBar reappear when scene is tapped
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(showBackButtonAndStatusBar))
view.addGestureRecognizer(tapGesture)
}
var detailItem: NSDate? {
didSet {
configureView()
}
}
//MARK:- Outside of the tapGesture in viewDidLoad everything below here is what I added
// bool to determine wether to hide the statusBar or not
var statusBarShouldBeHidden = false
// api method to allow the staus bar to be hidden
override var prefersStatusBarHidden: Bool{
return statusBarShouldBeHidden
}
// api method to animate status bar appearance/disappearance
override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation{
return .slide
}
#IBAction func buttonTapped(_ sender: UIButton) {
// 1. hide backBar button
navigationItem.setHidesBackButton(true, animated: false)
// 2. set bool to true
statusBarShouldBeHidden = true
UIView.animate(withDuration: 0.25){
// 3. api method to allow the statusBar to disappear
self.setNeedsStatusBarAppearanceUpdate()
}
}
//called when background is touched and added to tapGesture in viewDidLoad
#objc func showBackButtonAndStatusBar(){
// 1. set bool to false
statusBarShouldBeHidden = false
UIView.animate(withDuration: 0.25){
// 2. bring statusBar back
self.setNeedsStatusBarAppearanceUpdate()
}
// 3. bring backButton back
navigationItem.setHidesBackButton(false, animated: true)
}
}
How can I get the SplitViewVC to let me hide the statusBar?
It appears that you are trying to hide the status bar through the detail view controller. The status bar in the user interface is controlled only by the split view controller because it is on top of the view controller hierarchy. Therefore, the easiest way to control the behavior of the status bar is to subclass UISplitViewController and then override the prefersStatusBarHidden computed property in the subclass. Also, make sure you go to your storyboard and change the split view controller's custom class field in the Identity inspector to your subclass.
---Updated Answer---
#LanceSamaria Okay, I took your code above and tweaked some things. First of all, I only added the button action and not the tap gesture. Also, I commented out the hiding the back button, because this is important in the UI in order to be able to go back to the master view. Anyway, now when you click the button, the SplitViewController will hide the status bar. If you click the button again, then the status bar will reappear.
import UIKit
class DetailViewController: UIViewController {
#IBOutlet weak var detailDescriptionLabel: UILabel!
var statusBarShouldBeHidden = false
func configureView() {
// Update the user interface for the detail item.
if let detail = self.detailItem {
if let label = self.detailDescriptionLabel {
label.text = detail.description
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.configureView()
}
/* override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation{
return .slide
} */
var detailItem: NSDate? {
didSet {
// Update the view.
self.configureView()
}
}
#IBAction func buttonTapped(_ sender: UIButton) {
// 1. hide backBar button
//navigationItem.setHidesBackButton(true, animated: false)
// 2. set bool to true
statusBarShouldBeHidden = !statusBarShouldBeHidden
UIView.animate(withDuration: 0.25){
// 3. api method to allow the statusBar to disappear
guard let svc = self.splitViewController as? SplitViewController else { return }
svc.statusBarShouldBeHidden = self.statusBarShouldBeHidden
svc.setNeedsStatusBarAppearanceUpdate()
}
}
}
Also, one more really important thing. Below is my code for the split view controller subclass. Note that I use the same variable name "statusBarShouldBeHidden" in both the split view controller and the detail controller.
import UIKit
class SplitViewController: UISplitViewController {
var statusBarShouldBeHidden = false
override func viewDidLoad() {
super.viewDidLoad()
}
override var prefersStatusBarHidden: Bool {
return statusBarShouldBeHidden
}
}
Thank you for posting this question. This has helped my learn a lot trying to solve this problem. Please let me know if you still have a question about what this.
How do I add a button to navigation bar that appears only in a particular view controller? And also how to add different buttons to different view controller that is embedded in navigation controller.
You don't have to add buttons to navigation bar, rather you could add bar button items. If you want you can customise bar button item to meet your requirements like setting a custom image as suggested by #Pushpendra.
Programatically:
Your View Controller is responsible for providing bar button item(s) for it's navigation bar. Create bar button items inside each of your view controller's viewDidLoad() or in init() if you have overridden it.
Storyboards:
It's pretty handy to drag n drop bar button items from storyboard editor and have the outlets setup so that you can change the behaviour later.
If you are precisely looking to control the behaviour, then you can add or remove a bar button as and when needed depending on your conditional requirements.
class FooViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
/// Assuming this view controller presented/pushed with navigation controller
let buttonItem = UIBarButtonItem(barButtonSystemItem: .save, target: self, action: #selector(FooViewController.buttonItemAction(sender:)))
self.navigationItem.leftBarButtonItem = buttonItem
}
#IBAction func buttonItemAction(sender: UIBarButtonItem) {
/// some action
}
}
class BarViewController: UIViewController {
var buttonItem: UIBarButtonItem?
var showButtonItem = false
override func viewDidLoad() {
super.viewDidLoad()
/// Assuming this view controller presented/pushed with navigation controller
buttonItem = UIBarButtonItem(barButtonSystemItem: .bookmarks, target: self, action: #selector(BarViewController.buttonItemAction(sender:)))
self.navigationItem.leftBarButtonItem = buttonItem
}
#IBAction func buttonItemAction(sender: UIBarButtonItem) {
/// some action
}
#IBAction func toggleButtonItem(sender: UIButton) {
self.navigationItem.rightBarButtonItem = (self.showButtonItem == true) ? self.buttonItem : nil
}
}
If this is what you are not looking for then update your question along with the code that you have tried.
try this :-
extension UIViewController {
func addButton(img:String){
let imgIcon = UIImage(named: img)
let btn = UIBarButtonItem(image: imgIcon, style: .plain, target:
self, action: #selector(self.btnAction))
// if you want to set right button then add right bar button item
self.navigationItem.leftBarButtonItem = btn
}
func btnAction(){
}
func removeButton() {
self.navigationItem.leftBarButtonItem = nil
}
}
when you want to add button
in viewDidLoad :-
self.addButton(img:"imageName")
also if you want to perform separate action on all view controller then
call this on controller
override func btnAction() {
}
to remove :-
self.removeButton()
if you want to add different button on different controller add the button in viewDidLoad and remove in viewWillDisappear
Drag a bar button item in your navigation bar for the specific view controller in your storyboard
The best solution is
Create Viewcontroller inherit from UIViewController or UITableViewController and write a method for setupNavigationButton or buttonText or
(Better to add an action method on a super controller also)
eg:
-(void) setupNavigationButton {
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:#"button1" style:UIBarButtonItemStylePlain target:self action:#selector(buttonActin:)];
}
and call this method on viewDidLoad on the created controller
Next when you create your own controller add this viewcontroler as your parent view controller. So it will automatically add that view.
(You want to write an action on your controller)
Using above method, it saves only one line. But you can save more lines. Let's assume you want to change only text and action on that button.
If it is only you need to change text, write a method to return button text
(Following line for your baseviewcontroller)
-(NSString *) rightButtonText {
return #"";
}
and add following codes for baseviewcontroller
-(void)setNavigationControler {
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:[self rightButtonText] style:UIBarButtonItemStylePlain target:self action:#selector(buttonActin:)];
}
and call it on baseviewcontroller
Now your every view controller, you need to override rightButtonText and create selector method and do that action.
Assume you don't need to add that button for some viewcontroler. Then you have a few options
1) Remove baseviewcotroler inheritance from your viewcontroller
2) After call supper viewDidload add following code
self.navigationItem.rightBarButtonItem =
3) Override setNavigationControler method on your controller with the blank method body.
-(void)setNavigationControler {}
In my root view controller I set an array of bar button items with images and assign them to the right bar button.
When I push the next view controller my navigation bar resets and only displays a back button.
Any way to preserve the navigation bar as it was set on the root view controller so it will display on all pages?
As user1046037 has said you can set the item buttons while you are preparing the segue.
Example:
let helpViewController = HelpViewController(nibName: "HelpViewController", bundle: nil)
let someLeftButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.refresh, target: self, action: "someAction")
helpViewController.navigationItem.leftBarButtonItem = someLeftButton
helpViewController.navigationItem.leftItemsSupplementBackButton = true
navigationController?.pushViewController(helpViewController, animated: true)
This one is to preserve the left button item and the back one.
helpViewController.navigationItem.leftItemsSupplementBackButton = true
If you are going to use the same button in several Viewcontrollers you can create a BaseViewController setting up the button and his behaviors.
class AHBaseViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
configureNavigationBar()
// Configure Common status bar if you want too.
}
func configureNavigationBar() {
let someLeftButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.refresh, target: self, action: "someAction")
navigationItem.leftBarButtonItem = someLeftButton
navigationItem.leftItemsSupplementBackButton = true
}
}
Then just inherit it, in the viewControllers that you want to show the button(s).
class HelpViewController: AHBaseViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
}
When you segue between view controllers using Push, you're going to get the default "horizontal slide" navigation animation which. Try "present Modally" or "present as popover".
I have a question regarding the navigation bar.
As far as I understand from iOS: A view controller opened by a segue inherits the navigation bar of the parent view controller. Is this correct so far?
Is there a view controller within a stack "owns" the navigation bar in a complex segue stack (e.g. TableViewController that opens a TabBarController that opens ...)?
I very often run into the problem that I don't know where to get the actual navigation item in order to set the title or a bar button item.
In this case, I have the following controllers:
TabBarController
EventPostsViewController -> To display a list of posts, is a tabbed view within the TabBarController
CreatePostViewController -> To write a new post
So within the EventPostsViewController I can do this (and it works):
class EventPostsViewController: UITableViewController {
...
override func viewWillAppear(animated: Bool) {
...
// This solution works, but only for EventPostsViewController
self.tabBarController?.navigationItem.title = "text"
But within the CreatePostViewController, which is opened by a segue via EventPostsViewController, neither of this solutions work.
class CreatePostViewController: UIViewController {
...
override func viewWillAppear(animated: Bool) {
...
// Neither of these solutions works
self.navigationItem.title = "Text"
self.tabBarController?.navigationItem.title = "Text"
self.navigationController?.navigationItem.title = "Text"
How do I get the actual navigation bar/navigationItem?
Stupid simple mistake I repeat every time :)
I forgot to link my custom CreatePostViewController with the view controller using the interface builder.
This code now works:
class CreatePostViewController: UIViewController {
...
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated);
self.navigationController?.setNavigationBarHidden(false, animated: false)
// Set title
self.navigationItem.title = "Write Post"
// Add Submit button
var submitButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Done, target: self, action: "submitPost:")
self.navigationItem.rightBarButtonItem = submitButton
}
...
}