DataBinding 在自定义横向布局膨胀时失败答案

【问题标题】：DataBinding fails on custom landscape layout inflationDataBinding 在自定义横向布局膨胀时失败
【发布时间】：2020-02-23 06:30:57
【问题描述】：

我为横向创建了一个替代布局 XML 文件。使用DataBindingUtil 的膨胀在纵向模式下工作正常，但在加载自定义 XML 文件时在横向模式下崩溃。

使用 DataBinding 的布局膨胀：

class AskhostingFragment : Fragment() {

    private lateinit var binding : FragmentAskhostingBinding

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        binding = DataBindingUtil.inflate(inflater, R.layout.fragment_askhosting, container, false)

        return binding.root
    }
}

虽然我怀疑它们与问题相关，但我将这两个 XML 文件都包含在内。布局/fragment_askhosting.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/askhosting_cl_root"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/askhosting_cl_1"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@color/colorPrimaryDark"
            app:layout_constraintBottom_toTopOf="@+id/askhosting_cl_2"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">

            <TextView
                android:id="@+id/textView3"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="64dp"
                android:layout_marginTop="64dp"
                android:layout_marginEnd="64dp"
                android:text="@string/askhosting_option_stundenplan24"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                style="@style/TextLargeMultiline" />

            <Button
                android:id="@+id/button3"
                style="@style/Widget.AppCompat.Button.Colored"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="8dp"
                android:layout_marginEnd="32dp"
                android:layout_marginBottom="32dp"
                android:text="@string/stundenplan24"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/textView3"
                app:layout_constraintVertical_bias="1.0" />
        </androidx.constraintlayout.widget.ConstraintLayout>

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/askhosting_cl_2"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@color/colorPrimary"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/askhosting_cl_1">

            <ImageView
                android:id="@+id/imageView2"
                android:layout_width="110dp"
                android:layout_height="110dp"
                android:layout_marginTop="32dp"
                android:layout_marginEnd="32dp"
                android:contentDescription="@string/school_website"
                android:tint="@color/colorPrimaryDark"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/ic_web_black" />

            <TextView
                android:id="@+id/textView4"
                style="@style/TextLargeMultiline"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="64dp"
                android:layout_marginTop="16dp"
                android:layout_marginEnd="64dp"
                android:text="@string/askhosting_option_website"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.0"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/imageView2" />

            <Button
                android:id="@+id/button4"
                style="@style/Widget.AppCompat.Button.Colored"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="8dp"
                android:layout_marginEnd="32dp"
                android:layout_marginBottom="32dp"
                android:text="@string/school_website"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/textView4"
                app:layout_constraintVertical_bias="1.0" />
        </androidx.constraintlayout.widget.ConstraintLayout>

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

layout-land/fragment_askhosting.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/askhosting_cl_root"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/askhosting_cl_1"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@color/colorPrimaryDark"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@+id/askhosting_cl_2"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">

            <TextView
                android:id="@+id/textView3"
                style="@style/TextLargeMultiline"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="64dp"
                android:layout_marginTop="64dp"
                android:layout_marginEnd="64dp"
                android:text="@string/askhosting_option_stundenplan24"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <Button
                android:id="@+id/button3"
                style="@style/Widget.AppCompat.Button.Colored"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="8dp"
                android:layout_marginEnd="32dp"
                android:layout_marginBottom="32dp"
                android:text="@string/stundenplan24"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/textView3"
                app:layout_constraintVertical_bias="1.0" />
        </androidx.constraintlayout.widget.ConstraintLayout>

        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/askhosting_cl_2"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="@color/colorPrimary"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toEndOf="@+id/askhosting_cl_1"
            app:layout_constraintTop_toTopOf="parent">

            <ImageView
                android:id="@+id/imageView2"
                android:layout_width="110dp"
                android:layout_height="110dp"
                android:layout_marginTop="32dp"
                android:layout_marginEnd="32dp"
                android:contentDescription="@string/school_website"
                android:tint="@color/colorPrimaryDark"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@drawable/ic_web_black" />

            <TextView
                android:id="@+id/textView4"
                style="@style/TextLargeMultiline"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="64dp"
                android:layout_marginTop="16dp"
                android:layout_marginEnd="64dp"
                android:text="@string/askhosting_option_website"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.0"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/imageView2" />

            <Button
                android:id="@+id/button4"
                style="@style/Widget.AppCompat.Button.Colored"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="8dp"
                android:layout_marginEnd="32dp"
                android:layout_marginBottom="32dp"
                android:text="@string/school_website"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/textView4"
                app:layout_constraintVertical_bias="1.0" />
        </androidx.constraintlayout.widget.ConstraintLayout>

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

将设备切换到横向模式（或以横向启动应用程序）时的错误消息：

java.lang.IllegalArgumentException: The tag for fragment_askhosting is invalid. Received: layout-land/fragment_askhosting_0
        at net.hermlon.gcgtimetable.DataBinderMapperImpl.getDataBinder(DataBinderMapperImpl.java:42)
        at androidx.databinding.MergedDataBinderMapper.getDataBinder(MergedDataBinderMapper.java:74)
        at androidx.databinding.DataBindingUtil.bind(DataBindingUtil.java:199)
        at androidx.databinding.DataBindingUtil.inflate(DataBindingUtil.java:130)
        at androidx.databinding.DataBindingUtil.inflate(DataBindingUtil.java:95)
        at net.hermlon.gcgtimetable.ui.profile.create.AskhostingFragment.onCreateView(AskhostingFragment.kt:21)
        at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2600)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:881)
        at androidx.fragment.app.FragmentManagerImpl.addAddedFragments(FragmentManagerImpl.java:2100)
        at androidx.fragment.app.FragmentManagerImpl.executeOpsTogether(FragmentManagerImpl.java:1874)
        at androidx.fragment.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManagerImpl.java:1830)
        at androidx.fragment.app.FragmentManagerImpl.execPendingActions(FragmentManagerImpl.java:1727)
        at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange(FragmentManagerImpl.java:2663)
        at androidx.fragment.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManagerImpl.java:2613)
        at androidx.fragment.app.Fragment.performActivityCreated(Fragment.java:2624)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:904)
        at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManagerImpl.java:1238)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1303)
        at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange(FragmentManagerImpl.java:2659)
        at androidx.fragment.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManagerImpl.java:2613)
        at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:246)
        at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:542)
        at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:201)
        at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1425)
        at android.app.Activity.performStart(Activity.java:7825)
        at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3294)
        at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
        at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
        at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

引发异常的代码是生成文件app/build/generated/source/kapt/debug/net/hermlon/gcgtimetable/DataBinderMapperImpl.java中的如下函数：

@Override
  public ViewDataBinding getDataBinder(DataBindingComponent component, View view, int layoutId) {
    int localizedLayoutId = INTERNAL_LAYOUT_ID_LOOKUP.get(layoutId);
    if(localizedLayoutId > 0) {
      final Object tag = view.getTag();
      if(tag == null) {
        throw new RuntimeException("view must have a tag");
      }
      switch(localizedLayoutId) {
        case  LAYOUT_FRAGMENTASKHOSTING: {
          if ("layout/fragment_askhosting_0".equals(tag)) {
            return new FragmentAskhostingBindingImpl(component, view);
          }
          throw new IllegalArgumentException("The tag for fragment_askhosting is invalid. Received: " + tag);
        }
      }
    }
    return null;
  }

我猜 DataBinding 有一个问题，当它获得的布局的标签（无论是什么）由于横向布局的膨胀而改变时。这是一个错误还是 DataBinding 只是没有能力处理两个可变布局文件？

更新：这似乎是一段时间内的已知问题：https://issuetracker.google.com/issues/62740925 对于某些人来说，多个布局似乎可以正常工作：Android databinding with multiple layouts

【问题讨论】：

标签： android xml android-layout kotlin

【解决方案1】：

已解决：DataBinding 与横向布局完美配合，我只需要重新构建应用程序（构建->重新构建项目）。现在生成的代码如下所示，不再抛出异常：

@Override
  public ViewDataBinding getDataBinder(DataBindingComponent component, View view, int layoutId) {
    int localizedLayoutId = INTERNAL_LAYOUT_ID_LOOKUP.get(layoutId);
    if(localizedLayoutId > 0) {
      final Object tag = view.getTag();
      if(tag == null) {
        throw new RuntimeException("view must have a tag");
      }
      switch(localizedLayoutId) {
        case  LAYOUT_FRAGMENTASKHOSTING: {
          if ("layout/fragment_askhosting_0".equals(tag)) {
            return new FragmentAskhostingBindingImpl(component, view);
          }
          if ("layout-land/fragment_askhosting_0".equals(tag)) {
            return new FragmentAskhostingBindingLandImpl(component, view);
          }
          throw new IllegalArgumentException("The tag for fragment_askhosting is invalid. Received: " + tag);
        }
      }
    }
    return null;
  }

【讨论】：