Button is showing on screen but textField is not appearing every time. what is the error in my code? - swift

Question

I am setting textfied and a button programmatically. The button is showing when we run the code but not textfield. is there any problem with constraints or any other please help.
let submitButton: UIButton = {
let btn = UIButton(type:.system)
btn.backgroundColor = .blue
btn.setTitle("Login", for: .normal)
btn.tintColor = .white
btn.layer.cornerRadius = 5
btn.clipsToBounds = true
btn.translatesAutoresizingMaskIntoConstraints = false
return btn
}()
let textBox: UITextView = {
let textView = UITextView()
textView.text = "we are learning iOs"
textView.font = UIFont.boldSystemFont(ofSize: 18)
textView.textAlignment = .center
textView.translatesAutoresizingMaskIntoConstraints = false
return textView
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(textBox)
setupTexBoxLayout()
view.addSubview(submitButton)
setupSubmitBUttonLayout()
}
private func setupTexBoxLayout(){
textBox.topAnchor.constraint(equalTo: view.topAnchor, constant: 100).isActive = true
textBox.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 20).isActive = true
textBox.widthAnchor.constraint(equalToConstant: 100).isActive = true
}
private func setupSubmitBUttonLayout(){
submitButton.topAnchor.constraint(equalTo: textBox.bottomAnchor, constant: 100).isActive = true
submitButton.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 100).isActive = true
}
}

Answer 1

I have checked your code and debug it.
You have not specified height for textview so it is not showing it.
You can check the below code. I have added height constraint to it and it is displaying your textfield.
If you do not specify a height for textfield then it will take 0 height by default.
private func setupTexBoxLayout(){
textBox.topAnchor.constraint(equalTo: view.topAnchor, constant: 100).isActive = true
textBox.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 20).isActive = true
textBox.widthAnchor.constraint(equalToConstant: 300).isActive = true
textBox.heightAnchor.constraint(equalToConstant: 40).isActive = true
}