I am looking for a Swift5 Color Picker and I came across the Color Picker of Rastislav Mirek.
I added the Picker as a Swift Package and followed the instructions in the Read Me file. For a simple start I wanted open the Color Picker as a modal and select a color. This color is set as a background then in the root view controller.
Even after having followed all steps I do not seem to get it working. I added the delegate and a button to trigger the segue to the modal.
Xcode drops an error like
Use of undeclared type "ColorPickerDelegate"
and
Use of unresolved identifier "colorPickerController"
Does anyone have an hint for me?
class ViewController: UIViewController, ColorPickerDelegate {
#IBOutlet weak var hexTextField: UITextField!
#IBAction func applyColorPressed(_ sender: UIButton) {
//self.view.backgroundColor = UIColor.green
let navigationController = UINavigationController(rootViewController: colorPickerController)
present(navigationController, animated: true, completion: nil)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
}
Related
I uses a TableView Controller to hold UILable in my habit tracker app. However, after I run Xcode, all the UILable disappear.
import UIKit
import RealmSwiftNewIdeaCreation: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func createButtonPressed(_ sender: UIButton) {
self.dismiss(animated: true, completion: nil)
}
}
Did I miss anything here?
Prototype cells are not showing without data source.
You can use static cells from the content type of tableView in the attributes inspector pan.
I have a button called
#IBAction func likeIt(_ sender: Any) {
}
and I have two images called
like and likeSelected
how do I change the button picture when pressed and when not pressed
All you need to do is to give the button an initial image in the storyboard by setting the Image property.
Then after that you can set the button's image on highlighted state like below.
class ViewController: UIViewController {
#IBOutlet weak var buttonView: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
buttonView.setImage(UIImage(named: "likeSelected"), for: .highlighted)
}
}
Remember to check out Apple's documentation!
You're looking for UIButton.setImage(_:for:). For states, see UIControl.State.
I have been learning swift and have made the foundation of most of my app. I have the following storyboard
app storyboard
Everything works fine. For example, I have an unwind segue on the add course view controller that triggers when you press save and you are returned to the 'your courses' view controller.
When you are on the my courses view controller, you can select a course and the topics are displayed, you can then select a topic and you are taken to an update score view controller, this all works fine.
However, my problem is this. I want to make it so that when you select save in the updatescore view controller, an unwind segue is triggered (the same as in the add course) and you are returned to the list of topics in the topics view controller.
However, I have followed many tutorials and obviously got it working before. (My action method for the unwind segue is in the correct topics view controller) but when i press save, the unwind segue is not returning me to the topics view controller.
Could anyone suggest a reason for this? I have spent a lot of time trying to find an answer and gone through many tutorials but have not managed to solve it.
I have also included a screen shot of the connections of the triggered segues for my save button to show that it is set up. Showing triggered segue for save button
i have the following code in the update score view controller
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if saveButton === sender {
print("save button selected")
}
}
But even this is not getting triggered when I click on save.
Many thanks
UPDATE:
After following Ronatorys advice My view controller for the update score is as follows but it is still not working:
import UIKit
class UpdateScoreTableViewController: UITableViewController {
#IBOutlet weak var topicGettingUpdated: UITextField!
#IBOutlet weak var newScore: UITextField!
#IBOutlet weak var saveButton: UIBarButtonItem!
var index:Int?
var Topics:[String]!
var TopicToUpdate:String?
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
guard let uiBarButtonItem = sender as? UIBarButtonItem else {
print("There is no UIBarButtonItem sender")
return
}
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.section == 0 && indexPath.row == 0 {
newScore.becomeFirstResponder()
}
tableView.deselectRowAtIndexPath(indexPath, animated: true)
}
}
But the prepare for segue is not even getting triggered.
Like Craig in the comments said, it's not that easy to find the problem. So I just build a simple app where you can follow the steps as guide and see if you forgot something to setup the functionality right. Hope it will help you. Note: Code is in Swift 3.0, but should be easy to adopt to 2.*
1. Storyboard with two View Controllers:
2. Declare the action method for the unwind segue in the FirstViewController.swift:
class FirstViewController: UIViewController {
// action method for the unwind segue
#IBAction func updateScore(_ segue: UIStoryboardSegue) {
print("Back in the FirstViewController")
}
}
3. Connect the Save button in the Storyboard with the action method (with ctrl + drag):
4. Connect your Save button with the SecondViewController.swift file, to use it for checking in your prepareSegue method (with ctrl + drag):
5. Add the prepare(for:sender:) method to your SecondViewController.swift:
class SecondViewController: UIViewController {
#IBOutlet weak var saveButtonPressed: UIBarButtonItem!
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// check safely with guard that your save button is the sender and you can use it
// if not print message
guard let uiBarButtonItem = sender as? UIBarButtonItem else {
print("There is no UIBarButtonItem sender")
return
}
// check if you selected the save button
if saveButtonPressed == uiBarButtonItem {
print("save button selected")
}
}
}
Result:
The sample app you can find here
I did not manage to get the unwind segue to work but instead used
navigationController!.popViewControllerAnimated(true)
as a work around and this works fine.
I have been struggling to pass data between view controllers using segues. I have watched many youtube video tutorials and searched around on forums but I can't figure out why it won't work. I don't get any error messages but when I click the 'Button' the simulator crashes. I would love some help! Thanks!
Here is the code :
ViewController1 :
import UIKit
class ViewController: UIViewController {
#IBOutlet var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let destViewController : ViewController2 = segue.destinationViewController as! ViewController2
destViewController.labelText = textField.text!
}
}
ViewController2 :
import Foundation
import UIKit
class ViewController2 : UIViewController {
#IBOutlet var Label: UILabel!
var labelText : String = ""
override func viewDidLoad() {
Label.text = labelText
}
}
StoryBoard Image :
storyboard image
As stated on the comment the problem was that you were using a push segue on a UIViewController.
Please note that push and modal segues are deprecated... Please take a look at this post entry and let me know if you have any doubts
What's the difference between all the Selection Segues?
Make sure to enter some text in your label textField before tapping the button since you are passing that label's text to next scene by using force unwrap.
destViewController.labelText = textField.text! //here compiler expects that your textField has the value
I made a sample project using your same code and didn't get an error. There's nothing wrong with your code.
Try this: Go to your storyboard and check outlets inspector for each view controller and make sure you don't have an outlet to nowhere.
I am making a game for iOS with SpriteKit.
I have 2 Viewcontrollers. One is the GameViewController and the other one is the MenuViewController. Let's call them A and B respectively.
When the player dies, a function is called in GameScene.swift that launches a modal "Lost" Segue to B. There, the player can restart the game or buy a life and a "Back" Segue is called to A.
I need to dismiss the additional Views that get created each time I call a segue.
Problem is: I need the "Lost" Segue to send data about the Score to View B and I need the "Back" Segue to send data to View A about wether or not the player used a life.
I have implemented all this. But now I need to find how to dismiss old views that keep eating the device's memory, thus leading to lag and crash.
I have googled for hours and hours. No solution was adapted to my situation.
The solutions I found either caused my app to bug, data not to be passed or views not to be generated.
I will not add code here since there is a LOT. But I am sure the answer is actually really easy, just not for a beginner like me.
I think a possible solution would be an unwind segue from B to A ?
But do unwind segues pass data along ?
Moreover, I found no answer I could understand on how to use an unwind segue.
I exhausted all my possibilities. Stack Exchange is my last chance.
You definitely should use an unwind segue to return to the previous viewController, otherwise as you have found your memory usage increases until your apps quits.
I created the following example from your description. It uses a standard segue to move from the GameViewController to the MenuViewController and it uses an unwind segue to move from the MenuViewController back to the GameViewController.
The GameViewController has a Player Dies UIButton, a UITextField for entering a score, and a UILabel for displaying the lives.
The MenuViewController has a UILabel for showing the score, a Buy a Life UIButton for adding lives, and a Restart UIButton for returning to the GameViewController.
Here's the code:
GameViewController.swift
import UIKit
class GameViewController: UIViewController {
#IBOutlet weak var scoreTextField: UITextField!
#IBOutlet weak var livesLabel: UILabel!
var lives = 3
func updateLivesLabel() {
livesLabel.text = "Lives: \(lives)"
}
override func viewDidLoad() {
super.viewDidLoad()
updateLivesLabel()
}
// This is the function that the unwind segue returns to.
// You can call it anything you want, but it has to be in
// the viewController you are returning to, it must be tagged
// with #IBAction and it must take a UIStoryboardSegue as its
// only parameter.
#IBAction func returnFromMenu(segue: UIStoryboardSegue) {
print("We're back in GameViewController")
// Update the lives label based upon the value passed in
// prepareForSegue from the MenuViewController.
updateLivesLabel()
}
#IBAction func goPlayerDies(sender: UIButton) {
lives--
self.performSegueWithIdentifier("Lost", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "Lost" {
let destinationVC = segue.destinationViewController as! MenuViewController
destinationVC.score = Int(scoreTextField.text ?? "") ?? 0
destinationVC.lives = lives
}
}
}
MenuViewController.swift
import UIKit
class MenuViewController: UIViewController {
#IBOutlet weak var scoreLabel: UILabel!
var score = 0
var lives = 0
override func viewDidLoad() {
super.viewDidLoad()
scoreLabel.text = "Score: \(score)"
}
#IBAction func buyLife(sender: UIButton) {
lives++
}
#IBAction func goRestart(sender: UIButton) {
self.performSegueWithIdentifier("Back", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "Back" {
let destinationVC = segue.destinationViewController as! GameViewController
destinationVC.lives = lives
}
}
}
This is how you wire up the forward segue to be called programmatically:
Control-drag from ViewController icon to the MenuViewController:
Select Present Modally from the pop-up:
Click on the segue arrow between the viewControllers and give it an identifier in the Attributes Inspector:
This is how you wire up the unwind segue to be called programmatically:
Control-drag from ViewController icon to Exit icon:
Choose returnFromMenu from pop-up:
Click on the Unwind Segue in the Document Outline and give it the identifier "Back" in the Attributes Inspector on the right:
Alternate Answer
Instead of using segues, you can present and dismiss viewControllers manually. The advantage for your app is that the MenuViewController will be allocated only once and will persist for the life of the app. This same viewController will be presented and dismissed repeatedly, but it will not be deallocated which I suspect is leading to your crashes.
The GameViewController will be the initialViewController that is created by the Storyboard. The MenuViewController will be loaded in viewDidLoad of the GameViewController.
To make this work, you need to add an identifier to the MenuViewController so that it can be instantiated by name. Click on the MenuViewController in the Storyboard and set its Storyboard ID in the Identity Inspector:
Here is the code. Note that all mention of segues is gone. Note how viewWillAppear is used to update the viewControllers.
GameViewController.swift
import UIKit
class GameViewController: UIViewController {
#IBOutlet weak var scoreTextField: UITextField!
#IBOutlet weak var livesLabel: UILabel!
var menuViewController: MenuViewController?
var lives = 3
func updateLivesLabel() {
livesLabel.text = "Lives: \(lives)"
}
override func viewDidLoad() {
super.viewDidLoad()
menuViewController = self.storyboard!.instantiateViewControllerWithIdentifier("MenuViewController") as? MenuViewController
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
updateLivesLabel()
}
#IBAction func goPlayerDies(sender: UIButton) {
lives--
menuViewController?.score = Int(scoreTextField.text ?? "") ?? 0
menuViewController?.lives = lives
self.presentViewController(menuViewController!, animated: true, completion: nil)
}
}
MenuViewController.swift
import UIKit
class MenuViewController: UIViewController {
#IBOutlet weak var scoreLabel: UILabel!
var score = 0
var lives = 0
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
scoreLabel.text = "Score: \(score)"
}
#IBAction func buyLife(sender: UIButton) {
lives++
}
#IBAction func goRestart(sender: UIButton) {
let destinationVC = self.presentingViewController as! GameViewController
destinationVC.lives = lives
self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
}
}