CODEWITHSUNDEEP
androidandroid-studiokotlin
MakeTheErrorDie
MakeTheErrorDie

Reputation: 127

How to use getActivity() without returning NULL in other functions?

How do I use getActivity or activity in other functions outside of onCreate View, when I use activity in oncreateview or other functions it returns null. in a fragment.

Is there a way to store activity and use it as a variable in a function outside of oncreateview?

There are answers for this in java but I couldn't find in Kotlin, (interchanging between them is a bit confusing)

This is onCreateView

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {

        var mActivity = activity. // This returned Null

        phRecycler = view?.findViewById(R.id.recyle)
        E_shelf = view?.findViewById(R.id.E_shelf)
        phoneRecycler()

        return inflater.inflate(R.layout.fragment_home3, container, false)
    }

this is another function in the same fragment

 fun phoneRecycler() {

        //All Gradients
        //HSSFSheet sheet = readExcel();
        val TAG = "Main"
        val myMap: MutableMap<String, Int> = HashMap()
        myMap["Index"] = 0
        val LatestShelf = ArrayList<phonehelper>()
        val exs = ArrayList<phonehelper>()
        phoneRecycler!!.layoutManager = LinearLayoutManager(Activity, LinearLayoutManager.HORIZONTAL, false).   // activity returns null
...

I am getting Null value for activity wherever I put it, even in the OnCreateView, also this fragment is connected to a xml

Upvotes: 0

Views: 314

Answers (3)

Dr. Sa.M.
Dr. Sa.M.

Reputation: 2513

well I would suggest you to put



 phRecycler = view?.findViewById(R.id.recyle)
        E_shelf = view?.findViewById(R.id.E_shelf)
        phoneRecycler()

inside onViewCreated() method.

Also, your answer is Simple, use

/**
*as Per Docs, for requireActivity(), "Return the FragmentActivity this fragment is currently associated with."
*/
this.requireActivity()
// or simply
requireActivity()

/**
* another method would be 
* as per docs, for activity or getActivity(), "Return the FragmentActivity this fragment is currently associated with. May return null if the fragment is associated with a Context instead."
*/

val activity = this.activity
if(activity== null) throw error()

EDIT: Please Try This Code

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                          savedInstanceState: Bundle?): View? {


    return inflater.inflate(R.layout.fragment_home3, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    
    E_shelf = view.findViewById(R.id.E_shelf)
    phoneRecycler()

}

fun phoneRecycler() {

    //All Gradients
    //HSSFSheet sheet = readExcel();
    val TAG = "Main"
    val myMap: MutableMap<String, Int> = HashMap()
    myMap["Index"] = 0
    val LatestShelf = ArrayList<phonehelper>()
    val exs = ArrayList<phonehelper>()
    
    //remove any other variable declartion
    val phoneRecycler = view.findViewById(R.id.recyle)
    phoneRecycler.layoutManager = LinearLayoutManager(requireActivity(), LinearLayoutManager.HORIZONTAL, false).   // activity returns null
    ...

Upvotes: 1

tyczj
tyczj

Reputation: 73946

If a fragment is no longer attached to an activity then the activity variable is going to be null

you need to null check each time you try to use it

Upvotes: 1

Div MoD
Div MoD

Reputation: 158

I guess in your situation would be nice to replace logic from OnCreateView to OnActivityCreated method. Cause in this method getActivity != null always.

Upvotes: 0

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