NavHostFragment 无法从 XML 访问

我想尝试新的导航库。关注后本指南 https://developer.android.com/topic/libraries/architecture/navigation/navigation-implementing我在运行时遇到错误：

Caused by: android.view.InflateException: Binary XML file line #11: Binary XML file line #11: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment androidx.navigation.fragment.NavHostFragment: make sure class name exists, is public, and has an empty constructor that is public

在资源文件中activity_home.xml。这个文件非常简单：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    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:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.home.HomeActivity">

    <fragment
        android:id="@+id/fragment_navigation_host"
        android:name="androidx.navigation.fragment.NavHostFragment"
        app:defaultNavHost="true"
        app:navGraph="@navigation/navigation_home" />

</FrameLayout>

我查看了源代码NavHostFragment我注意到它使用android.support.v4.app.Fragment虽然我的整个应用程序使用androidx.fragment.app.Fragment.

我不相信这是问题所在，但我在下面包含了一些依赖项：

// AndroidX
implementation     "androidx.appcompat:appcompat:$appCompatVersion"
implementation     "androidx.constraintlayout:constraintlayout:$constraintLayoutVersion"
implementation     "androidx.lifecycle:lifecycle-extensions:$lifecycleVersion"
implementation     "androidx.recyclerview:recyclerview:$recyclerViewVersion"
implementation     "androidx.room:room-runtime:$roomVersion"
implementation     "androidx.room:room-rxjava2:$roomVersion"

kapt               "androidx.room:room-compiler:$roomVersion"

// Navigation
implementation     "android.arch.navigation:navigation-fragment-ktx:$navigationVersion"
implementation     "android.arch.navigation:navigation-ui-ktx:$navigationVersion"

正如您所看到的，我使用的是 AndroidX 中的库（导航除外），因为它可能尚未迁移。我在 Google 上唯一能找到的地方androidx.navigation is here https://developer.android.com/jetpack/docs/getting-started。不幸的是 Gradle 无法下载它。

Edit

我的内部还启用了 jetifier 工具gradle.properties.

android.enableJetifier=true
android.useAndroidX=true

Update

它已在 Android Studio 3.2 Canary 17 中修复，如中所述这个答案 https://stackoverflow.com/a/50385411/4386668。不要忘记使缓存失效并重新启动以删除代码中的警告。

我也有这个头痛，因为我正在关注 Android Kotlin 基础教程：https://codelabs.developers.google.com/codelabs/kotlin-android-training-add-navigation/index.html#3 https://codelabs.developers.google.com/codelabs/kotlin-android-training-add-navigation/index.html#3这是适合我的代码

<androidx.fragment.app.FragmentContainerView
        android:id="@+id/myNavHostFragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:navGraph="@navigation/navigation"
        app:defaultNavHost="true"/>

显然教程还没有更新。另外在依赖项中需要更新库..

....    
implementation "androidx.navigation:navigation-fragment:2.3.0"
implementation "androidx.navigation:navigation-ui:2.3.0"

我使用的是Android Studio 4.0。