Android Jetpack NavigationUI 设置AppBar的menu

Fragment的切换 通常伴随顶部ActionBar的menu的变换

为了方便统一管理 引入了NavigationUI

下面弄个demo 点击右上角是哪个点 出现设置界面

点击设置页面跳转到设置页面。点击设置中的返回进行返回

页面代码

NavigationUIActivity

package com.anguomob.jecpack.activityimport androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.util.Log
 import android.view.Menu
 import android.view.MenuItem
 import androidx.navigation.NavController
 import androidx.navigation.NavDestination
 import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.NavigationUI
 import com.anguomob.jecpack.R
 import com.anguomob.jecpack.databinding.ActivityNavigationBinding
 import com.anguomob.jecpack.databinding.ActivityNavigationUiactivityBindingclass NavigationUIActivity : AppCompatActivity() {private lateinit var binding: ActivityNavigationUiactivityBindingprivate lateinit var navController: NavControllerprivate lateinit var appBarConfiguration: AppBarConfigurationprivate  val TAG = "NavigationUIActivity"override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)binding = ActivityNavigationUiactivityBinding.inflate(layoutInflater)setContentView(binding.root)val navHostFragment =supportFragmentManager.findFragmentById(R.id.fragmentContainerView2) as NavHostFragmentnavController = navHostFragment.navControllerappBarConfiguration = AppBarConfiguration.Builder(navController.graph).build()NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration)//监听页面切换navController.addOnDestinationChangedListener(object :NavController.OnDestinationChangedListener{override fun onDestinationChanged(controller: NavController,destination: NavDestination,arguments: Bundle?) {Log.e(TAG, "onDestinationChanged: ", )}})}override fun onCreateOptionsMenu(menu: Menu?): Boolean {menuInflater.inflate(R.menu.menu_settings, menu)return super.onCreateOptionsMenu(menu)}override fun onOptionsItemSelected(item: MenuItem): Boolean {//先交给NavigationUI  如果搞不定则使用默认return NavigationUI.onNavDestinationSelected(item,navController) || super.onOptionsItemSelected(item)}//返回键支持override fun onSupportNavigateUp(): Boolean {return NavigationUI.navigateUp(navController, appBarConfiguration) || super.onSupportNavigateUp()}
 }

布局代码

HomeFragment

package com.anguomob.jecpack.fragmentimport android.os.Bundle
 import androidx.fragment.app.Fragment
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import android.widget.Button
 import androidx.navigation.Navigation
 import com.anguomob.jecpack.R
 import com.anguomob.jecpack.databinding.ActivityNavigationBinding
 import com.anguomob.jecpack.databinding.FragmentHomeNavigationBindingclass HomeNavigationFragment : Fragment() {private lateinit var binding: FragmentHomeNavigationBindingoverride fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,savedInstanceState: Bundle?): View? {binding = FragmentHomeNavigationBinding.inflate(inflater)
 //        inflater.inflate(R.layout.fragment_home_navigation, container, false)return binding.root}override fun onActivityCreated(savedInstanceState: Bundle?) {super.onActivityCreated(savedInstanceState)binding.btHome.setOnClickListener {val args = HomeNavigationFragmentArgs("jack",18).toBundle()val findNavController = Navigation.findNavController(it)findNavController.navigate(R.id.action_homeNavigationFragment_to_detailNavigationFragment,args)}}
 }

请注意 这次跳转是不生效的。因为这个fragment的graph文件里面没有对详情页面做配置

Home布局

SettingFragment

package com.anguomob.jecpack.fragmentimport android.os.Bundle
 import android.view.*
 import androidx.fragment.app.Fragment
 import com.anguomob.jecpack.R// 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"/*** A simple [Fragment] subclass.* Use the [SettingFragment.newInstance] factory method to* create an instance of this fragment.*/
 class SettingFragment : Fragment() {override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,savedInstanceState: Bundle?): View? {//为了确保onCreateOptionsMenu 生效setHasOptionsMenu(true)// Inflate the layout for this fragmentreturn inflater.inflate(R.layout.fragment_setting, container, false)}override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {//当前页面不展示三个点menu.clear()super.onCreateOptionsMenu(menu, inflater)}}

布局

graph文件

代码分享的流程不对。应该是先创建fragment-》创建graph文件->创建页面activity文件 这样一个顺序

大家凑合着看吧

menu代码

位置