android.widget.LinearLayout cannot be cast to android.widget.GridLayout with view binding

Question

Please help if you observe what's going wrong !

MainActivity.kt

class MainActivity : AppCompatActivity() {

    lateinit var binding : ActivityMainBinding
    lateinit var buttonBinding: LayoutButtonBinding
    lateinit var textBinding: LayoutTextBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        textBinding = LayoutTextBinding.bind(binding.root)
        buttonBinding = LayoutButtonBinding.bind(binding.root)

           buttonBinding.btnOne.setOnClickListener {
                Toast.makeText(this, "Button Clear Clicked", Toast.LENGTH_SHORT).show()
            }





    }
}

activity_main.xml

<LinearLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <include
        layout="@layout/layout_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="bottom">

        <include
            layout="@layout/layout_button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom" />
    </LinearLayout>


</LinearLayout>

layout_button.xml

<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:columnCount="4"
    android:orientation="vertical"
    android:rowCount="5">


    <Button
        android:id="@+id/btn_clear"
        style="@style/CalButtonFunctional"
        android:layout_column="0"
        android:layout_row="0"
        android:text="C" />

    <Button
        android:id="@+id/btn_percentage"
        style="@style/CalButtonFunctional"
        android:layout_column="1"
        android:layout_row="0"
        android:text="%" />

    <Button
        style="@style/CalButtonFunctional"
        android:layout_column="2"
        android:layout_row="0"
        android:text="B" />


    <Button
        android:id="@+id/btn_divide"
        style="@style/CalButtonArithmatic"
        android:layout_column="3"
        android:layout_row="0"
        android:text="/" />


    <Button
        android:id="@+id/btn_seven"
        style="@style/CalButtonFunctional"
        android:layout_column="0"
        android:layout_row="1"
        android:text="7" />


    <Button
        android:id="@+id/btn_eight"
        style="@style/CalButtonFunctional"
        android:layout_column="1"
        android:layout_row="1"
        android:text="8" />


    <Button
        android:id="@+id/btn_nine"
        style="@style/CalButtonFunctional"
        android:layout_column="2"
        android:layout_row="1"
        android:text="9" />


    <Button
        android:id="@+id/btn_multply"
        style="@style/CalButtonArithmatic"
        android:layout_column="3"
        android:layout_row="1"
        android:text="x" />


    <Button
        android:id="@+id/btn_six"
        style="@style/CalButtonFunctional"
        android:layout_column="0"
        android:layout_row="2"
        android:text="6" />


    <Button
        android:id="@+id/btn_five"
        style="@style/CalButtonFunctional"
        android:layout_column="1"
        android:layout_row="2"
        android:text="5" />

    <Button
        android:id="@+id/btn_four"
        style="@style/CalButtonFunctional"
        android:layout_column="2"
        android:layout_row="2"
        android:text="4" />

    <Button
        android:id="@+id/btn_minus"
        style="@style/CalButtonArithmatic"
        android:layout_column="3"
        android:layout_row="2"
        android:text="-" />

    <Button
        android:id="@+id/btn_three"
        style="@style/CalButtonFunctional"
        android:layout_column="0"
        android:layout_row="3"
        android:text="3" />

    <Button
        android:id="@+id/btn_two"
        style="@style/CalButtonFunctional"
        android:layout_column="1"
        android:layout_row="3"
        android:text="2" />


    <Button
        android:id="@+id/btn_one"
        style="@style/CalButtonFunctional"
        android:layout_column="2"
        android:layout_row="3"
        android:text="1" />


    <Button
        android:id="@+id/btn_plus"
        style="@style/CalButtonArithmatic"
        android:layout_column="3"
        android:layout_row="3"
        android:text="+" />


    <Button
        android:id="@+id/btn_equal"
        style="@style/CalButtonArithmatic"
        android:layout_column="3"
        android:layout_row="4"
        android:text="=" />

    <Button
        android:id="@+id/btn_doubleZero"
        style="@style/CalButtonFunctional"
        android:layout_column="0"
        android:layout_row="4"
        android:text="00" />

    <Button
        android:id="@+id/btn_zero"
        style="@style/CalButtonFunctional"
        android:layout_column="1"
        android:layout_row="4"
        android:text="0" />

    <Button
        android:id="@+id/btn_dot"
        style="@style/CalButtonFunctional"
        android:layout_column="2"
        android:layout_row="4"
        android:text="." />


</GridLayout>

layout_text.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    android:orientation="vertical">


    <TextView
        android:id="@+id/textViewCalculations"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="1+2+2"
        android:textAlignment="textEnd"
        android:textSize="30sp" />


    <TextView
        android:id="@+id/textCalResult"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="40"
        android:textAlignment="textEnd"
        android:textSize="40sp" />


</LinearLayout>

Problem Encountered: App is crashing with Exception: android.widget.LinearLayout cannot be cast to android.widget.GridLayout while binding button_layout in activity at line 21 at

buttonBinding = LayoutButtonBinding.bind(binding.root)

Answer 1

That is not how you should use LayoutButtonBinding and LayoutTexBinding. We need to assign an id to included part, this way in ActivityMainBinding we will have the access to their respective bindings.

MainActivity.kt

class MainActivity : AppCompatActivity() {
lateinit var binding : ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding = ActivityMainBinding.inflate(layoutInflater)
    setContentView(binding.root)


    binding.layoutButton.btnOne.setOnClickListener {
        Toast.makeText(this, "Button Clear Clicked", Toast.LENGTH_SHORT).show()
    }

 }
}

activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

<include
    android:id="@+id/layout_text"
    layout="@layout/layout_text"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="bottom">

    <include
        android:id="@+id/layout_button"
        layout="@layout/layout_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom" />
</LinearLayout>