How to use an ArrayAdapter in a Fragment with Kotlin
11,750
The problem is in this constructor call:
spinner.adapter = ArrayAdapter(
this,
R.layout.support_simple_spinner_dropdown_item,
resources.getStringArray(R.array.atoms)
) as SpinnerAdapter
The argument this
must be a reference to a Context
, and a Fragment
is not a Context
. In an Activity
it works because an Activity
is a Context
.
The solution is to replace this
with activity
:
spinner.adapter = ArrayAdapter(
activity,
R.layout.support_simple_spinner_dropdown_item,
resources.getStringArray(R.array.atoms)
)
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Author by
a2krocks
Updated on September 14, 2022Comments
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a2krocks over 1 year
I am trying to to create a
Spinner
inside aFragment
but I am getting error in theArrayAdapter
constructor call. I don't know why, but it has a red underline. Other than that, there is no error. When I'm using the sameArrayAdapter
in anActivity
it works, but in aFragment
, it gives an error.My
FirstFragment.kt
:class FirstFragment : Fragment() { private var mListener: OnFragmentInteractionListener? = null override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? { // Inflate the layout for this fragment return inflater!!.inflate(R.layout.fragment_first, container, false) } override fun onViewCreated(view: View?, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) /*Find the id of spinner*/ val spinner = lol /*set an adapter with strings array*/ spinner.adapter = ArrayAdapter(this, R.layout.support_simple_spinner_dropdown_item, resources.getStringArray(R.array.atoms)) as SpinnerAdapter? /*set click listener*/ spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener { override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) { val num = when (spinner.selectedItem.toString()) { "H" -> editText.setText("1") "He" -> editText.setText("4") "C" -> editText.setText("12") "O" -> editText.setText("16") else -> editText.setText("") } } override fun onNothingSelected(parent: AdapterView<*>) { /*Do something if nothing selected*/ } } button.setOnClickListener { if ( editText2.text.toString().length > 0 && editText.text.toString().length > 0) { val num2 = editText.text.toString().toDouble() val num1 = editText2.text.toString().toDouble() val num = num1/num2 textView.setText("$num moles") } else { textView.setText("Please Enter a correct value") } } } }
My
fragment_first.xml
:<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" xmlns:app="http://schemas.android.com/apk/res-auto" tools:context="com.a3.aakap.ftrial.FirstFragment"> <android.support.constraint.ConstraintLayout android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/textView" android:layout_width="294dp" android:layout_height="80dp" android:layout_weight="1" android:text="Amswer : No of Moles" android:textAlignment="center" android:textSize="20sp" app:layout_anchorGravity="right|top" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.556" /> <TextView android:id="@+id/textView1" android:layout_width="143dp" android:layout_height="46dp" android:layout_weight="1" android:text="Amount in Grams " android:textAlignment="center" android:textSize="20sp" app:layout_anchorGravity="left|bottom" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.066" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.305" /> <Spinner android:id="@+id/lol" android:layout_width="145dp" android:layout_height="57dp" app:layout_anchorGravity="left|top" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.07" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.136" /> <Button android:id="@+id/button" android:layout_width="138dp" android:layout_height="43dp" android:text="Calculate" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.788" /> <EditText android:id="@+id/editText" android:layout_width="148dp" android:layout_height="57dp" android:ems="10" android:hint="Gram" android:inputType="numberDecimal|number" app:layout_anchorGravity="bottom|center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.762" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.137" /> <EditText android:id="@+id/editText2" android:layout_width="148dp" android:layout_height="57dp" android:ems="10" android:hint="Gram" android:inputType="numberDecimal|number" app:layout_anchorGravity="center_horizontal|center" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.716" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.288" /> </android.support.constraint.ConstraintLayout> </FrameLayout>
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a2krocks over 6 yearsThank you for help
-
Jhon Fredy Trujillo Ortega over 6 yearsif it works for you please choose it like the correct answer
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a2krocks over 6 yearsDone , Thank you for help
-
AlexTa over 6 yearsIn Kotlin you access
activity
directly, no needed to callgetActivity()
, and to SpinnerAdapter casting is redundant. -
Michael over 3 yearsIn Fragment class, I use
activity as Context
. Otherwise there is type mismatch error in Kotlin.