页面导航Navigation

基本说明

• 做了两个Fragment
• 然后做了两个动作，将两个可以进行切换

HomeFragment代码

import android.os.Bundle
import com.example.navigation.HomeFragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import androidx.fragment.app.Fragment
import com.example.navigation.R
import androidx.navigation.NavController
import androidx.navigation.Navigation

/**
 * A simple [Fragment] subclass.
 * Use the [HomeFragment.newInstance] factory method to
 * create an instance of this fragment.
 */
class HomeFragment : Fragment() {
    // TODO: Rename and change types of parameters
    private var mParam1: String? = null
    private var mParam2: String? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        if (arguments != null) {
            mParam1 = requireArguments().getString(ARG_PARAM1)
            mParam2 = requireArguments().getString(ARG_PARAM2)
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_home, container, false)
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        val button: Button
        button = requireView().findViewById(R.id.button_home)
        button.setOnClickListener { v ->
            val controller = Navigation.findNavController(v)
            controller.navigate(R.id.action_homeFragment_to_detailFragment2)
        }
    }

    companion object {
        // TODO: Rename parameter arguments, choose names that match
        // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
        private const val ARG_PARAM1 = "param1"
        private const val ARG_PARAM2 = "param2"

        /**
         * Use this factory method to create a new instance of
         * this fragment using the provided parameters.
         *
         * @param param1 Parameter 1.
         * @param param2 Parameter 2.
         * @return A new instance of fragment HomeFragment.
         */
        // TODO: Rename and change types and number of parameters
        fun newInstance(param1: String?, param2: String?): HomeFragment {
            val fragment = HomeFragment()
            val args = Bundle()
            args.putString(ARG_PARAM1, param1)
            args.putString(ARG_PARAM2, param2)
            fragment.arguments = args
            return fragment
        }
    }
}

DetailFragment

package com.example.navigation

import android.os.Bundle
import com.example.navigation.DetailFragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.navigation.Navigation
import com.example.navigation.R

/**
 * A simple [Fragment] subclass.
 * Use the [DetailFragment.newInstance] factory method to
 * create an instance of this fragment.
 */
class DetailFragment : Fragment() {
    // TODO: Rename and change types of parameters
    private var mParam1: String? = null
    private var mParam2: String? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        if (arguments != null) {
            mParam1 = requireArguments().getString(ARG_PARAM1)
            mParam2 = requireArguments().getString(ARG_PARAM2)
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_detail, container, false)
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        requireView().findViewById<View>(R.id.button_detail)
            .setOnClickListener(Navigation.createNavigateOnClickListener(R.id.action_detailFragment_to_homeFragment))
    }

    companion object {
        // TODO: Rename parameter arguments, choose names that match
        // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
        private const val ARG_PARAM1 = "param1"
        private const val ARG_PARAM2 = "param2"

        /**
         * Use this factory method to create a new instance of
         * this fragment using the provided parameters.
         *
         * @param param1 Parameter 1.
         * @param param2 Parameter 2.
         * @return A new instance of fragment DetailFragment.
         */
        // TODO: Rename and change types and number of parameters
        fun newInstance(param1: String?, param2: String?): DetailFragment {
            val fragment = DetailFragment()
            val args = Bundle()
            args.putString(ARG_PARAM1, param1)
            args.putString(ARG_PARAM2, param2)
            fragment.arguments = args
            return fragment
        }
    }
}

my_nav.xml

<?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/my_nav"
    app:startDestination="@id/homeFragment">

    <fragment
        android:id="@+id/homeFragment"
        android:name="com.example.navigation.HomeFragment"
        android:label="fragment_home"
        tools:layout="@layout/fragment_home" >
        <action
            android:id="@+id/action_homeFragment_to_detailFragment2"
            app:destination="@id/detailFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim" />
    </fragment>
    <fragment
        android:id="@+id/detailFragment"
        android:name="com.example.navigation.DetailFragment"
        android:label="fragment_detail"
        tools:layout="@layout/fragment_detail" >
        <action
            android:id="@+id/action_detailFragment_to_homeFragment"
            app:destination="@id/homeFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim" />
    </fragment>
</navigation>

fragment_detail.xml

<?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/my_nav"
    app:startDestination="@id/homeFragment">

    <fragment
        android:id="@+id/homeFragment"
        android:name="com.example.navigation.HomeFragment"
        android:label="fragment_home"
        tools:layout="@layout/fragment_home" >
        <action
            android:id="@+id/action_homeFragment_to_detailFragment2"
            app:destination="@id/detailFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim" />
    </fragment>
    <fragment
        android:id="@+id/detailFragment"
        android:name="com.example.navigation.DetailFragment"
        android:label="fragment_detail"
        tools:layout="@layout/fragment_detail" >
        <action
            android:id="@+id/action_detailFragment_to_homeFragment"
            app:destination="@id/homeFragment"
            app:enterAnim="@anim/nav_default_enter_anim"
            app:exitAnim="@anim/nav_default_exit_anim" />
    </fragment>
</navigation>

fragment_home.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".HomeFragment">
    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
       android:layout_marginLeft="140dp"
        android:layout_marginTop="200dp"
        android:text="HomeFragment"
        android:textSize="23dp" />

    <Button
        android:id="@+id/button_home"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="150dp"
        android:layout_marginTop="300dp"
        android:text="Button"
        android:textSize="23dp" />
</FrameLayout>