1 依赖

implementation'androidx.navigation:navigation-fragment:2.1.0'

2 资源

在res目录下创建navigation目录,并且在该目录下创建一个Navigation resource file的xml文件

创建xml文件.png
打开你创建的xml文件并且选择design界面

添加元素.png

选择元素.png
点击某个元素右边中间的小圈连接其他元素添加action,这些action就是你想要的各个元素之间的跳转切换等

添加动作.png
切换到text界面,自动生成如下代码

<?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.xml"
    app:startDestination="@id/helloFragment">

    <fragment
        android:id="@+id/helloFragment"
        android:name="com.zhu.hello.feature.fragment.HelloFragment"
        android:label="HelloFragment" >
        <action
            android:id="@+id/action_helloFragment_to_findFragment"
            app:destination="@id/findFragment" />
    </fragment>
    <fragment
        android:id="@+id/findFragment"
        android:name="com.zhu.hello.feature.fragment.FindFragment"
        android:label="FindFragment">
        <action
            android:id="@+id/action_findFragment_to_friendFragment"
            app:destination="@id/friendFragment" />
    </fragment>
    <fragment
        android:id="@+id/mineFragment"
        android:name="com.zhu.hello.feature.fragment.MineFragment"
        android:label="fragment_mine"
        tools:layout="@layout/fragment_mine">
        <action
            android:id="@+id/action_mineFragment_to_helloFragment"
            app:destination="@id/helloFragment" />
    </fragment>
    <fragment
        android:id="@+id/friendFragment"
        android:name="com.zhu.hello.feature.fragment.FriendFragment"
        android:label="FriendFragment">
        <action
            android:id="@+id/action_friendFragment_to_mineFragment"
            app:destination="@id/mineFragment" />
    </fragment>
</navigation>

app:startDestination="@id/helloFragment"表示主页面

3 布局

MainActivity的布局文件activity_main.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".feature.MainActivity">

   <fragment
        android:id="@+id/container"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:defaultNavHost="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:navGraph="@navigation/nav" />
</androidx.constraintlayout.widget.ConstraintLayout>

4 实现

比如从HelloFragment切换到FindFragment

   @OnClick(R.id.btn_hello)
   public void onViewClicked(View view) {
       Navigation.findNavController(view).navigate(R.id.action_helloFragment_to_findFragment);
   }