The text in the Modal View Controller does not change in the view controller - ios

Question

I am a beginner in iOS.
I have a problem that I made a class named ModalViewController. To make this as a common class, I didn't give any text to the textView in this class. So I tried to change the text when I present this viewController.
But I am getting an error. How can I fix it?
In addition, how can I change the margin value in text view?
Main.storyboard
MainViewController.swift
import UIKit
var modalview : ModalViewController!
class ViewController: UIViewController {
...
#IBAction func Onclick(_ sender: Any) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let myAlert = storyboard.instantiateViewController(withIdentifier: "ModalViewController")
myAlert.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
myAlert.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
modalview.modalCustomAlert.text = "test test test text" // Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
self.present(myAlert, animated: true, completion: nil)
}
ModalViewController.swift
import Foundation
import UIKit
class ModalViewController : UIViewController {
#IBOutlet weak var modalCustomAlert: UITextView!
#IBOutlet weak var cancelButton: UIButton!
#IBOutlet weak var okButton: UIButton!
#IBAction func cancelPress(_ sender: Any) {
}
#IBAction func okPress(_ sender: Any) {
}
override func viewDidLoad() {
super.viewDidLoad()
modalCustomAlert.layer.cornerRadius = 8
}
#IBAction func modalbutton(_ sender: Any) {
}
}
Edited start
I tried to assign a value but there was no change in the error.
var modalview = ModalViewController()
...
#IBAction func Onclick(_ sender: Any) {
...
modalview.modalCustomAlert.text = "test test test text" // Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
}
Edited TWO start
I've tried this already. But when I saw the answer from #PGDev, I tried it again, but it showed the same error.
#IBAction func Onclick(_ sender: Any) {
...
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let myAlert = storyboard.instantiateViewController(withIdentifier: "ModalViewController") as! ModalViewController
myAlert.modalPresentationStyle = .overCurrentContext
myAlert.modalTransitionStyle = .crossDissolve
myAlert.modalCustomAlert.text = "test test test text" // Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
self.present(myAlert, animated: true, completion: nil)
}

Answer 1

Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
modalview.modalCustomAlert.text = "test test test text"
The exception is because either modalview is nil or modalCustomAlert is nil.
1. You've created modalview as implicitly unwrapped optional like,
var modalview : ModalViewController!
Check if you've assigned any value to modalview before accessing it. If you haven't this will result in crash.
2. Next, you have created an outlet of modalCustomAlert,
#IBOutlet weak var modalCustomAlert: UITextView!
This is also an implicitly unwrapped optional. Check if the outlet is connected properly. If it isn't it will raise the runtime exception.
If an implicitly unwrapped optional is nil and you try to access its
wrapped value, you’ll trigger a runtime error. The result is exactly
the same as if you place an exclamation mark after a normal optional
that doesn’t contain a value.
Edit-1:
var modalview = ModalViewController()
The above code won't connect the outlets in ModalViewController. That's the reason modalCustomAlert is nil and result in exception.
Create modalview using storyboard like,
let modalview = storyboard.instantiateViewController(withIdentifier: "ModalViewController")
One question though. What's the reason to create modalview and myAlert separately if they both are of type ModalViewController?
Edit-2:
I don't think there is even a need to create modalview. Simply use myAlert view at the line where you're getting the exception. So the code for ViewController goes like,
class ViewController: UIViewController {
//....
#IBAction func Onclick(_ sender: Any) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let myAlert = storyboard.instantiateViewController(withIdentifier: "ModalViewController") as! ModalViewController
myAlert.modalPresentationStyle = .overCurrentContext
myAlert.modalTransitionStyle = .crossDissolve
myAlert.modalCustomAlert.text = "test test test text"
self.present(myAlert, animated: true, completion: nil)
}
}
Edit-3:
Got that. Just didn't realise that you're accessing modalCustomAlert before the outlets are created.
First of all, in ModalViewController create a property text. And in viewDidLoad() add this text as modalCustomAlert.text, i.e.
class ModalViewController : UIViewController {
//rest of the code....
var text: String? //here....
override func viewDidLoad() {
super.viewDidLoad()
modalCustomAlert.layer.cornerRadius = 8
self.modalCustomAlert.text = text //here....
}
}
Now, when creating alertView, replace
myAlert.modalCustomAlert.text = "test test test text"
with
myAlert.text = "test test test text"

Answer 2

Please add one new variable String in Your ModalViewController
class ModalViewController : UIViewController {
var objTextViewString:String = ""
override func viewDidLoad() {
super.viewDidLoad()
self.modalCustomAlert.text = self.objTextViewString
}
}
On ModelViewController Present Please pass String On added String Variable..That's It..!!
class ViewController: UIViewController {
//....
#IBAction func Onclick(_ sender: Any) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let myAlert = storyboard.instantiateViewController(withIdentifier: "ModalViewController") as! ModalViewController
myAlert.modalPresentationStyle = .overCurrentContext
myAlert.modalTransitionStyle = .crossDissolve
myAlert.objTextViewString = "test test test test"
self.present(myAlert, animated: true, completion: nil)
}
}