I have a fragment manager that I created, on my main activity as below

supportFragmentManager.beginTransaction().replace(R.id.fragment1, ProduceFragment.newInstance("Title")).commit()

and new Instance function that saves the title on bundle

from different file (Produce.kt) as below

fun newInstance(title: String): ProduceFragment {
            val frag = ProduceFragment()
            val bundle = Bundle()
            bundle.putString(titleKey, title)
            Log.d("XXX", "title $title")
            return frag }

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        val text =savedInstanceState?.getBundle(titleKey)
        binding.title.text = text.toString()

I see the title on Log.d but I kept getting null. How do I use the bundle to change my title.text?

>Solution :

In your code, you are only creating the bundle but not using it anywhere. You need to attach that bundle to the fragment.

fun newInstance(title: String): ProduceFragment {
    val frag = ProduceFragment()
    val bundle = Bundle()
    bundle.putString(titleKey, title)
    frag.arguments = bundle
    return frag
}

And to retrieve this title value, you can use:

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    val text = arguments?.getString(titleKey)
    binding.title.text = text.toString()