Fragment management access error visible return false

Question

I am managing the fragment as show and hide. But when I try to access the method in one fragment, I get null and I ask the question. Of course, method access works well in other fragments that manage the same.

This is my hide code.

private fun replaceFragment(fragment: Fragment) {
        supportFragmentManager.beginTransaction().apply {
            if (fragment.isAdded) {
                show(fragment)
            } else {
                add(R.id.container_activity_main, fragment)
            }

            supportFragmentManager.fragments.forEach {
                if (it != fragment && it.isAdded) {
                    hide(it)
                }
            }
        }.commit()
    }

my show code

supportFragmentManager.beginTransaction().show(fragmentName).commit()

fragmentName is arbitrarily specified for the question

If you take a log of the codes below, false, false, and true are displayed.

${fragmentName!!.isVisible}, ${fragmentName!!.isDetached} ,${fragmentName!!.userVisibleHint}

Here the fragment is visible to me but isVisible always return false . I don't know why this happens.

Even if onStop is called in hide , if you show, onCreateView is called and there should be a view, but the view becomes null and the app does not work.

I don't know why this is happening. The view is visible, but visible returns false.

Answer 1

For the visibility issue you should use :

     fragment.userVisibleHint

instead of:

     fragment.isVisible

Like mentioned in the documentation.

Fragment.isVisible doesn't work with all fragment use cases, it can be true only if fragment.isAdded == true, fragment.isHidden == false, fragment.view != null, fragment.view.windowToken != null and fragment.view.visibility == View.VISIBLE. Only if all these conditions are met in your implementation of the fragment, then the isVisible method returns true.