android - 与抽屉导航一起使用时，工具栏后退按钮不起作用

Question

下面是代码

我已经使用 AppbarConfiguraion 定义了我所有的顶级目的地。

class MainActivity : DaggerAppCompatActivity(), NavigationView.OnNavigationItemSelectedListener {

    lateinit var navController: NavController
    lateinit var binding: MainActivityBinding
    lateinit var appBarConfiguration: AppBarConfiguration

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
        navController = findNavController(R.id.navigation)
        setSupportActionBar(binding.toolbar)
        supportActionBar!!.setDisplayShowHomeEnabled(true)

        appBarConfiguration = AppBarConfiguration(
            setOf(
                R.id.homeFragment,
                R.id.bulletinsFragment,
                R.id.serviceFragment,
                R.id.paymentsFragment,
                R.id.feedBackFragment,
                R.id.formsFragment,
                R.id.surveysFragment
            ),
            drawer_layout)
        setupActionBarWithNavController(
            this, navController, appBarConfiguration
            )

        val toggle = ActionBarDrawerToggle(
            this,
            drawer_layout,
            binding.toolbar,
            R.string.navigation_drawer_open,
            R.string.navigation_drawer_close
        )
        drawer_layout.addDrawerListener(toggle)
        toggle.syncState()
        sideNV.setNavigationItemSelectedListener(this)
    }

    override fun onBackPressed() {
        if ((drawer_layout as DrawerLayout).isDrawerOpen(GravityCompat.START)) {
            (drawer_layout as DrawerLayout).closeDrawer(GravityCompat.START)
        } else {
            findNavController(R.id.navigation).navigateUp()
        }
    }

    override fun onNavigationItemSelected(item: MenuItem): Boolean {

        when (item.itemId) {
            R.id.nav_home, R.id.nav_service, R.id.nav_payments, R.id.nav_forms, R.id.nav_bulletins,
            R.id.nav_surveys, R.id.nav_feedbacks -> {
                navController.navigate(item.itemId)
            }
        }
        (drawer_layout as DrawerLayout).closeDrawer(GravityCompat.START)
        return true
    }

    override fun onSupportNavigateUp() = findNavController(R.id.navigation).navigateUp()
}

当从顶级 fragment 移动到其他 fragment 时，会显示后退箭头，但单击它会打开抽屉本身。单击系统后退按钮时，它工作正常。

list

<activity
        android:name=".home.MainActivity"
        android:label="@string/app_name"
        android:parentActivityName=".home.MainActivity"
        android:theme="@style/AppTheme.NoActionBar">
</activity>

Answer 1

class MainActivity : DaggerAppCompatActivity(), NavigationView.OnNavigationItemSelectedListener {

    lateinit var navController: NavController
    lateinit var binding: MainActivityBinding
    lateinit var appBarConfiguration: AppBarConfiguration

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
        navController = findNavController(R.id.navigation)
        setSupportActionBar(binding.toolbar)
        supportActionBar!!.setDisplayShowHomeEnabled(true)

        appBarConfiguration = AppBarConfiguration(
            setOf(
                R.id.homeFragment,
                R.id.bulletinsFragment,
                R.id.serviceFragment,
                R.id.paymentsFragment,
                R.id.feedBackFragment,
                R.id.formsFragment,
                R.id.surveysFragment
            ),
            drawer_layout
        )
        setupActionBarWithNavController(
            this, navController, appBarConfiguration
        )

        val toggle = ActionBarDrawerToggle(
            this,
            drawer_layout,
            binding.toolbar,
            R.string.navigation_drawer_open,
            R.string.navigation_drawer_close
        )
        drawer_layout.addDrawerListener(toggle)
        toggle.syncState()
        sideNV.setNavigationItemSelectedListener(this)
        toolbar?.setNavigationOnClickListener {
            findNavController(R.id.navigation).navigateUp(appBarConfiguration)
        }
    }

    override fun onBackPressed() {
        if ((drawer_layout as DrawerLayout).isDrawerOpen(GravityCompat.START)) {
            (drawer_layout as DrawerLayout).closeDrawer(GravityCompat.START)
        } else {
            super.onBackPressed()
        }
    }

    override fun onNavigationItemSelected(item: MenuItem): Boolean {

        when (item.itemId) {
            R.id.nav_home, R.id.nav_service, R.id.nav_payments, R.id.nav_forms, R.id.nav_bulletins,
            R.id.nav_surveys, R.id.nav_feedbacks -> {
                navController.navigate(item.itemId)
            }
        }
        (drawer_layout as DrawerLayout).closeDrawer(GravityCompat.START)
        return true
    }

    override fun onSupportNavigateUp() = findNavController(R.id.navigation).navigateUp()
}

我刚刚更改了我的代码并添加了工具栏 NavigationOnClickListener 并且在该监听器中我刚刚添加了 navigateUp(appBarConfiguration)。onBackPressed() 也有轻微的变化，因为在我之前的代码中，即使我们位于堆栈中的最后一个 fragment ，它也不会关闭应用程序