Cannot assign onClick to a button in kotlin

I am working on an android studio project which is partially built in kotlin and the rest in in java. I have never worked with kotlin before this project and currently I have found myself spending hours trying to implement a simple onclick to a button. I know this question has been asked a lot but most of the solutions I have tried do not work.

here is my xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/folioPageFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<FrameLayout
    android:id="@+id/webViewLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_above="@+id/indicatorLayout">

    <com.folioreader.ui.view.WebViewPager
        android:id="@+id/webViewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <com.folioreader.ui.view.FolioWebView
        android:id="@+id/folioWebView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

<com.folioreader.ui.view.LoadingView
    android:id="@+id/loadingView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:maxVisibleDuration="10000"
    tools:visibility="invisible" >
</com.folioreader.ui.view.LoadingView>

<com.folioreader.ui.view.VerticalSeekbar
    android:id="@+id/scrollSeekbar"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_above="@+id/indicatorLayout"
    android:layout_alignParentRight="true"
    android:layout_marginRight="2dp"
    android:animateLayoutChanges="true"
    android:thumb="@drawable/thumb"
    android:visibility="invisible" />

<Button
        android:text="Button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" tools:layout_editor_absoluteY="655dp"
        tools:layout_editor_absoluteX="161dp"
        android:id="@+id/buttonVasko"
        android:layout_marginTop="530dp"
        android:layout_marginLeft="150dp"

        android:layout_alignParentTop="true" 
        android:layout_alignParentStart="true"
        android:layout_marginStart="0dp"

/>
<LinearLayout
    android:id="@+id/indicatorLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:gravity="center"
    android:orientation="horizontal"
    android:paddingTop="2dp"
    android:paddingBottom="2dp"
    android:visibility="gone">

    <TextView
        android:id="@+id/minutesLeft"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#888888"
        android:textSize="7sp" />

    <TextView
        android:id="@+id/pagesLeft"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#bbbbbb"
        android:textSize="8sp" />
</LinearLayout>

this is the beginning of the onCreateView function:

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

    buttonVasko.setOnClickListener(object:View.OnClickListener {
        override fun onClick(view:View) {
            Toast.makeText(context,"WORK!!!", Toast.LENGTH_LONG).show()
        }// end onClick
    })

this is the error I receive when running the code:

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.folioreader.android.sample, PID: 3862
java.lang.IllegalStateException: Could not find method zoko(View) in a 
parent or ancestor Context for android:onClick attribute defined on view 
class androidx.appcompat.widget.AppCompatButton with id 'buttonVasko'

I also tried placing the setOnClickListener at the very end in the onCreateView function in case there was a line of code that needed to be written before the setOnClickListener but the result is the same.

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Full FolioPageFragment is here: https://codeshare.io/5PlwDw

Solution

You’ve already inflated your fragment as mRootView. You can set your onClick listener in onViewCreated. Here is the code

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    view.findViewById<Button>(R.id.buttonVasko).setOnClickListener {
       
    }
}

And you should delete these static view imports.

import kotlinx.android.synthetic.main.folio_page_fragment.*
import kotlinx.android.synthetic.main.folio_page_fragment.view.*

Hope it will work.

Answered By — Ensar Bayhan

Answer Checked By — Senaida (FixIt Volunteer)

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0