Kotlin - Type mismatch: required: Context found: Context?

Question

I tried to make a PopupMenu

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    menu_btn.setOnClickListener {
        var menu: PopupMenu?
        menu = PopupMenu(this.context, it)
        menu.inflate(R.menu.card_menu)

        menu.setOnMenuItemClickListener {
            when(it.itemId) {
                R.id.menu_modify -> { Toast.makeText(context, "Modify", Toast.LENGTH_LONG).show()
                    true }

                R.id.menu_delete -> { Toast.makeText(context, "Delete", Toast.LENGTH_LONG).show()
                    true }

                else -> false
            }
        }

        menu.show()
    }
}

but I get wiggly red line under

menu = PopupMenu(this.context, it)

That says: Type mismatch. Required: Context Found: Contex?

and even when I use !! - I get this error

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
    at com.example.emek1.myapplication.FragmentOne.onCreate(FragmentOne.kt:24)
    at android.support.v4.app.Fragment.performCreate(Fragment.java:2414)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1418)
    at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1195)
    at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:1078)
    at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:117)
    at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2408)
    at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
    at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2243)
    at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:654)
    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:146)
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1244)
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1092)
    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1622)

Note: that it's not in MainActivity.kt It's a Fragment.

If its fragment you can not "menu_btn.setOnClickListener" in onCreate method. As view will not be initialized there. Try adding this method in "onCreateView" method after inflating view. — Dhaval Patel, Oct 11 '18 at 05:59
Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — Zoe, Oct 11 '18 at 15:16

score 7 · Answer 1 · answered Oct 11 '18 at 06:00

7

Write this code

context?.let {
    menu = PopupMenu(it, view)
}

Here view will be your anchor view of the popup.

instead of

menu = PopupMenu(this.context, it)

answered Oct 11 '18 at 06:00

Avijit Karmakar

8,890
6
44
59

score 3 · Answer 2 · edited Sep 15 '20 at 15:21

3

If it was a fragment you should call context like this.

menu = PopupMenu(activity!!, it)

or if you have the latest library you can do something like this

menu = PopupMenu(requireActivity(), it)

edited Sep 15 '20 at 15:21

Aswathy

654
1
12
26

answered Sep 15 '20 at 15:03

Arisqi Setyawan

31
2

score 2 · Answer 3 · answered Oct 11 '18 at 06:00

The NullPointerException arises from fact that onCreate() runs before onCreateView() which inflates your view hierarchy. Therefore menu_btn is still null, because not found. Have another look at the Fragments lifecycle.

For the popup it might be better to use the Context from the View parameter it.context.

Kotlin - Type mismatch: required: Context found: Context?

3 Answers3

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