java.lang.NullPointerException: Missing required v

2020-07-02 10:29发布

Android Studio 3.6

in app/build.gradle:

android {
viewBinding.enabled = true

Here my xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/bluetoothBottonMainContainer"
        android:layout_width="0dp"
        android:layout_height="104dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <View
            android:id="@+id/viewPointNotSelect"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:background="@drawable/circle_transparent"
            app:layout_constraintBottom_toBottomOf="@+id/separator"
            app:layout_constraintEnd_toStartOf="@+id/separator"
app:layout_constraintTop_toTopOf="parent" />

and another xml the unclude prev. xml:

 <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/bottonContainer"
        android:layout_width="0dp"
        android:layout_height="104dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <include
            android:id="@+id/qrBottonContainer"
            layout="@layout/qr_bottom_container"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent" />

here my activity:

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

the app is build and run. Nice.

Now I move id - android:id="@+id/bluetoothBottonMainContainer"

to outer container like this:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/bluetoothBottonMainContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="0dp"
        android:layout_height="104dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <View
            android:id="@+id/viewPointNotSelect"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:background="@drawable/circle_transparent"
            app:layout_constraintBottom_toBottomOf="@+id/separator"
            app:layout_constraintEnd_toStartOf="@+id/separator"
            app:layout_constraintTop_toTopOf="parent" />

app is build, but when run I get runtime error in this line:

binding = QrBluetoothSwipeActivityBinding.inflate(layoutInflater)

error:

10-25 11:11:51.290 E/AndroidRuntime(14128): FATAL EXCEPTION: main
10-25 11:11:51.290 E/AndroidRuntime(14128): Process: com.myproject.debug, PID: 14128
10-25 11:11:51.290 E/AndroidRuntime(14128): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myproject.debug/com.myproject.ui.actviity.QRBluetoothSwipeActivity}: java.lang.NullPointerException: Missing required view with ID: bluetoothBottonMainContainer
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread.-wrap11(ActivityThread.java)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.os.Handler.dispatchMessage(Handler.java:102)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.os.Looper.loop(Looper.java:148)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread.main(ActivityThread.java:5417)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at java.lang.reflect.Method.invoke(Native Method)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
10-25 11:11:51.290 E/AndroidRuntime(14128): Caused by: java.lang.NullPointerException: Missing required view with ID: bluetoothBottonMainContainer
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.myproject.databinding.BluetoothBottomContainerBinding.bind(BluetoothBottomContainerBinding.java:114)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.myproject.databinding.QrBluetoothSwipeActivityBinding.bind(QrBluetoothSwipeActivityBinding.java:76)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.myproject.databinding.QrBluetoothSwipeActivityBinding.inflate(QrBluetoothSwipeActivityBinding.java:62)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.myproject.databinding.QrBluetoothSwipeActivityBinding.inflate(QrBluetoothSwipeActivityBinding.java:52)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at com.myproject.ui.actviity.QRBluetoothSwipeActivity.onCreate(QRBluetoothSwipeActivity.kt:31)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.Activity.performCreate(Activity.java:6251)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
10-25 11:11:51.290 E/AndroidRuntime(14128):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
10-25 11:11:51.290 E/AndroidRuntime(14128):     ... 9 more
10-25 11:11:51.291 W/ActivityManager(  780):   Force finishing activity com.myproject.debug/com.myproject.ui.actviity.QRBluetoothSwipeActivity
10-25 11:11:51.307 I/Icing   (11529): Indexing done com.google.android.gms-apps

9条回答
够拽才男人
2楼-- · 2020-07-02 11:12

The solution is remove the id of the main container. And put in other container inside the parent.

1.- Layout

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

2.- Include Layout

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/example2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent">
    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
查看更多
仙女界的扛把子
3楼-- · 2020-07-02 11:15

I encountered this issue but in my case the issue is the include flag. The workaround I found is to make the view id to be the same as the id of the root view of the included layout.

activity_layout.xml

<LinearLayout>
    <include android:id="@+id/widget1" layout="@layout/my_widget" />
</LinearLayout>

my_wideget.xml

<LinearLayout
    android:id="@+id/widget1">
</LinearLayout>
查看更多
我只想做你的唯一
4楼-- · 2020-07-02 11:15

getRootView() returns the included layout and can make changes in it

查看更多
Melony?
5楼-- · 2020-07-02 11:16

Update

This should be fixed in latest Beta, Carnary versions of Android Studio

Still there is an issue when using View Binding with material tab layout tab items which is reported here and have not fixed yet.


This is bug in ViewBinding which is reported in the issue tracker in following places.

查看更多
孤傲高冷的网名
6楼-- · 2020-07-02 11:17

In my case , I removed the id inside the included layout and it works properly !

main.xml

    <RelativeLayout>   
    ....
    <include
        include="@layout/included_layout"   
        android:id="@+id/view_included_layout"/>
    </RelativeLayout>

included_layout.xml

`   <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/top_level_layout">  <!-- Remove this id -->    
        ....
    </LinearLayout>
`

My Android Studio version is 3.6.2 and version of build.gradle is 3.6.1

查看更多
三岁会撩人
7楼-- · 2020-07-02 11:19

Please check, maybe you have the same layout files in different modules.

查看更多
登录 后发表回答