title: How to use an ArrayAdapter in a Fragment with Kotlin
body: <p>I am trying to to create a <code>Spinner</code> inside a <code>Fragment</code> but I am getting error in the <code>ArrayAdapter</code> 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 same <code>ArrayAdapter</code> in an <code>Activity</code> it works, but in a <code>Fragment</code>, it gives an error.</p>
  
  <p>My <code>FirstFragment.kt</code>:</p>
  
  <pre><code>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&lt;*&gt;, view: View, position: Int, id: Long) {
                  val num = when (spinner.selectedItem.toString()) {
                      "H" -&gt; editText.setText("1")
                      "He" -&gt; editText.setText("4")
                      "C" -&gt; editText.setText("12")
                      "O" -&gt; editText.setText("16")
                      else -&gt; editText.setText("")
                  }
              }
  
              override fun onNothingSelected(parent: AdapterView&lt;*&gt;) {
                  /*Do something if nothing selected*/
              }
          }
  
          button.setOnClickListener {
              if (
                  editText2.text.toString().length &gt; 0 &amp;&amp;
                  editText.text.toString().length &gt; 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")
              }
          }
      }
  }
  </code></pre>
  
  <p>My <code>fragment_first.xml</code>:</p>
  
  <pre><code>&lt;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"&gt;
  
      &lt;android.support.constraint.ConstraintLayout
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"&gt;
  
          &lt;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" /&gt;
  
          &lt;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" /&gt;
  
          &lt;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" /&gt;
  
          &lt;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" /&gt;
  
          &lt;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" /&gt;
  
          &lt;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" /&gt;
  
      &lt;/android.support.constraint.ConstraintLayout&gt;
  
  &lt;/FrameLayout&gt;
  </code></pre>