最近在学Jetpack Navigation组件
但是在写navigation资源文件的时候
Preview 显示不出来
一开始以为是Android Studio的bug
后来一查才知道就navigation.xml文件少了layout属性
<?xml version="1.0" encoding="utf-8"?>
<navigation 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/nav_ui" tools:ignore="UnusedNavigation" app:startDestination="@id/fragment1">
<fragment android:id="@+id/fragment1" android:name="com.czb.jetpacknavigation.Fragment1" android:label="Fragment1"
tools:layout="@layout/fragment1">
<action android:id="@+id/action_fragment1_to_fragment2" app:destination="@id/navigation"/>
</fragment>
<navigation android:id="@+id/navigation" app:startDestination="@id/fragment2">
<fragment android:id="@+id/fragment2" android:name="com.czb.jetpacknavigation.Fragment2"
tools:layout="@layout/fragment2"
android:label="Fragment2">
<action android:id="@+id/action_fragment2_to_fragment3" app:destination="@id/fragment3"/>
<action android:id="@+id/action_fragment2_to_mainActivity2" app:destination="@id/mainActivity2"/>
</fragment>
<fragment android:id="@+id/fragment3" android:name="com.czb.jetpacknavigation.Fragment3"
tools:layout="@layout/fragment3"
android:label="Fragment3"/>
<activity android:id="@+id/mainActivity2" android:name="com.czb.jetpacknavigation.MainActivity2"
tools:layout="@layout/activity_main2"
android:label="MainActivity2"/>
</navigation>
</navigation>
加上layout属性后就可以预览了
