android.widget.LinearLayout 无法通过视图绑定强制转换为 android.widget.GridLayout

Question

如果您发现出了什么问题，请帮忙！

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>

遇到的问题：应用程序崩溃并出现异常：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

这不是您应该使用LayoutButtonBinding 和LayoutTexBinding 的方式。 我们需要为包含的部分分配一个 id，这样在 ActivityMainBinding 中我们就可以访问它们各自的绑定。

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>