mypackage:layout/activity_main 中的二进制 XML 文件第 18 行：错误膨胀类 androidx.fragment.app.FragmentContainerView答案

【问题标题】：Binary XML file line #18 in mypackage:layout/activity_main: Error inflating class androidx.fragment.app.FragmentContainerViewmypackage:layout/activity_main 中的二进制 XML 文件第 18 行：错误膨胀类 androidx.fragment.app.FragmentContainerView
【发布时间】：2021-04-21 13:55:32
【问题描述】：

当我将“上下文上下文”属性添加到适配器构造函数后，尝试将“getContext()”参数传递给我在片段中创建的适配器实例时，会发生此错误。完全不知道该怎么做，我在 SO 中找到的一些决定没有帮助。我将非常感谢任何建议。

错误文本：

java.lang.RuntimeException: Unable to start activity ComponentInfo{space.rodionov.swedishdriller/space.rodionov.swedishdriller.MainActivity}: android.view.InflateException: Binary XML file line #18 in space.rodionov.swedishdriller:layout/activity_main: Binary XML file line #18 in space.rodionov.swedishdriller:layout/activity_main: Error inflating class androidx.fragment.app.FragmentContainerView

在片段中：

@AndroidEntryPoint
class DrillerFragment : Fragment(R.layout.cardstack_layout), CardStackListener {

    private val viewModel: DrillerViewModel by viewModels()
    private var drillerAdapter = JavaDrillerAdapter(JavaDrillerAdapter.JavaDrillerDiff(), false, requireContext())

在适配器中：

public class JavaDrillerAdapter extends ListAdapter<Word, JavaDrillerAdapter.JavaDrillerViewHolder> {

    private Boolean nativToForeign;

    Context context;

    protected JavaDrillerAdapter(@NonNull DiffUtil.ItemCallback diffCallback, Boolean nativToForeign, Context context) {
    super(diffCallback);
    this.nativToForeign = nativToForeign;
    this.context = context;
}

activity_main.xml：

<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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.appcompat.widget.Toolbar
        //blablabla
        />

    <androidx.fragment.app.FragmentContainerView //THIS IS THE LINE #18 THE ERROR REFERS TO
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/bottom_nav"
        android:layout_below="@id/toolbar"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        //blablabla

        />

</RelativeLayout>

在 MainActivity.kt 中：

class MainActivity : AppCompatActivity() {
    private lateinit var navController: NavController

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main) // THIS IS ALSO THE LINE MENTIONED IN THE ERROR

        val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
        navController = navHostFragment.findNavController()
        // and so on

【问题讨论】：

如果你在onCreateView中转移这个实例化你有同样的行为吗
谢谢，我搬了它，一切正常

标签： java android kotlin android-fragments android-navigation

【解决方案1】：

尝试在onCreate方法中移动你的适配器初始化，context在视图初始化之前是不可用的：

@AndroidEntryPoint
class DrillerFragment : Fragment(R.layout.cardstack_layout), CardStackListener {

    private val viewModel: DrillerViewModel by viewModels()
    private var drillerAdapter: JavaDrillerAdapter? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        drillerAdapter = JavaDrillerAdapter(JavaDrillerAdapter.JavaDrillerDiff(), false, requireContext())
    }

【讨论】：