我有一個底部的活動BottomNavigationView，FloatingActionButton四fragment秒。我想FloatingActionButton僅在我在 'fragment1' 和 'fragment2 時顯示，并在選擇 'fragment3' 或 'fragment4' 時隱藏它。在啟動應用程式時，“fragment1”與 一起顯示，FloatingActionButton當我導航到“fragment3”時我設法隱藏了它。但問題是當我從 'fragment3' 或 'fragment4' 導航回 'fragment1' 時，FloatingActionButton它仍然是隱藏的。
以下是xml我的“HomeActivity”
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@ id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@ id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@ id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@ id/fab_one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_hide_category"
app:layout_anchor="@id/bottom_appbar"/>
<fragment
android:id="@ id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="50dp"
app:defaultNavHost="true"
app:navGraph="@navigation/mobile_navigation"
app:layout_anchor="@id/bottom_appbar"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
以下是我在我的“HomeActivity”，我把它從代碼onCreateView中的fragments到隱藏它。
fun hideFabOne(){
binding.fabOne.hide()
}
Then I add the below code in the 'HomeActivity' and call it in from the fragments to show the FAB, the app crashes on launch.
fun showFabOne(){
binding.fabOne.show()
}
Edit:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
Caused by: kotlin.UninitializedPropertyAccessException: lateinit property binding has not been initialized
at com.abc.xyz.ui.activities.HomeActivity.showFabOne(HomeActivity.kt:110)
at com.abc.xyz.ui.fragments.HomeFragment.onCreateView(HomeFragment.kt:102)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2963)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1647)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3128)
at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3065)
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2988)
at androidx.fragment.app.FragmentStateManager.ensureInflatedView(FragmentStateManager.java:392)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:281)
at androidx.fragment.app.FragmentLayoutInflaterFactory.onCreateView(FragmentLayoutInflaterFactory.java:140)
at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:135)
at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:319)
at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:298)
at android.view.LayoutInflater.tryCreateView(LayoutInflater.java:1067)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:995)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:959)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1121)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1082)
at android.view.LayoutInflater.inflate(LayoutInflater.java:680)
at android.view.LayoutInflater.inflate(LayoutInflater.java:532)
at com.abc.xyz.databinding.ActivityHomeBinding.inflate(ActivityHomeBinding.java:59)
at com.abc.xyz.databinding.ActivityHomeBinding.inflate(ActivityHomeBinding.java:53)
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:38)
2021-11-10 11:23:40.557 13300-13300/com.abc.xyz E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3808)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
uj5u.com熱心網友回復：
由于您使用app:navGraphmake useaddOnDestinationChangedListener來控制FloatingActionButton.
里面HomeActivity做這個
navController.addOnDestinationChangedListener { _, destination, _ ->
if(destination.id == /*FRAGMENT ID*/) {
// hide
} else {
// show
}
}
uj5u.com熱心網友回復：
我不知道你的代碼，我使用了一個演示來嘗試重現崩潰和你想要的功能。
我重用了代碼并將您的 XML 添加到我的 XML 檔案中。
什么原因
我在不同的方法中添加了一些日志來檢查呼叫順序以查找崩潰原因。
我的解決方案：將代碼移到Fragment中的onResume方法中
這是我的代碼 MainActivity
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
lateinit var fab: FloatingActionButton
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
Log.d("MainActivity", "TANCOLO===> onCreate 000 ")
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
val navView: BottomNavigationView = binding.navView
fab = findViewById(R.id.fab_one)
Log.d("MainActivity", "TANCOLO===> onCreate 111, fab = $fab ")
val navController = findNavController(R.id.nav_host_fragment_activity_main)
val appBarConfiguration = AppBarConfiguration(
setOf(
R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications
)
)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
首頁片段
class HomeFragment : Fragment() {
private lateinit var homeViewModel: HomeViewModel
private var _binding: FragmentHomeBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
Log.d("HomeFragment", "TANCOLO===> onCreateView() ")
homeViewModel =
ViewModelProvider(this).get(HomeViewModel::class.java)
_binding = FragmentHomeBinding.inflate(inflater, container, false)
val root: View = binding.root
val textView: TextView = binding.textHome
homeViewModel.text.observe(viewLifecycleOwner, Observer {
textView.text = it
})
return root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
Log.d("HomeFragment", "TANCOLO===> onViewCreated ")
//get the FAB and show it.
// (requireActivity() as MainActivity).fab.apply {
// Log.d("HomeFragment", "TANCOLO===> onViewCreated, fab = $this ")
// visibility = View.VISIBLE
// }
}
override fun onResume() {
super.onResume()
Log.d("HomeFragment", "TANCOLO===> onResume ")
//get the FAB and show it.
(requireActivity() as MainActivity).fab.apply {
Log.d("HomeFragment", "TANCOLO===> onResume, fab = $this ")
visibility = View.VISIBLE // or View.GONE
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
轉載請註明出處，本文鏈接：https://www.uj5u.com/net/357965.html
標籤：android kotlin android-fragments floating-action-button