错误找不到片段构造函数

Question

一些用户遇到“无法找到片段构造函数”错误 但我无法在我的模拟器和测试设备上重现此错误

我阅读了这些资源 [找不到 Fragment 构造函数]，[找不到片段构造函数（设置活动）]， [无法找到 Fragment 构造函数 kotlin] 但这没有帮助。

所有资源都告诉我向片段添加一个空构造函数，但在我的情况下，每个片段都有一个空构造函数。

设置工具栏共享stackTrace和

stackTrace

java.lang.RuntimeException: Unable to start activity ComponentInfo{{packageName}/{packageName}.presentation.main.MainActivity}: androidx.fragment.app.o$d: Unable to instantiate fragment a9.a: could not find Fragment constructor
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2805)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2883)
    at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4726)
    at android.app.ActivityThread.-wrap18(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1619)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6523)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:857)
Caused by: androidx.fragment.app.o$d: Unable to instantiate fragment a9.a: could not find Fragment constructor
    at androidx.fragment.app.c0$b.a(:5)
    at androidx.fragment.app.h0.a(Unknown Source:2)
    at androidx.fragment.app.i0.<init>(Unknown Source:13)
    at androidx.fragment.app.c0.W(:8)
    at androidx.fragment.app.c0.b(:23)
    at androidx.fragment.app.u.lambda$init$1(:1)
    at androidx.fragment.app.u.i(Unknown Source:0)
    at androidx.fragment.app.t.a(Unknown Source:2)
    at androidx.activity.ComponentActivity.onCreate(:1)
    at androidx.fragment.app.u.onCreate(Unknown Source:0)
    at {packageName}.presentation.main.MainActivity.onCreate(Unknown Source:0)
    at android.app.Activity.performCreate(Activity.java:7013)
    at android.app.Activity.performCreate(Activity.java:7004)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
    at androidx.test.runner.MonitoringInstrumentation.callActivityOnCreate(MonitoringInstrumentation.java:2)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2758)
    ... 10 more
Caused by: java.lang.NoSuchMethodException: <init> []
    at java.lang.Class.getConstructor0(Class.java:2320)
    at java.lang.Class.getConstructor(Class.java:1725)
    ... 26 more

MainActivity

• 我使用“com.google.android.material.bottomnavigation.BottomNavigationView”
• 链接到导航图（共4个片段）

@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
    lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        val navFragment = supportFragmentManager.findFragmentById(R.id.mainActivityContainer) as NavHostFragment
        val navController = navFragment.navController
        binding.bottomNavi.setupWithNavController(navController)
    }

    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        this.intent = intent
    }

    override fun onResume() {
        super.onResume()
        val dest = intent.getStringExtra("destination")
        dest?.let {
            when (it) {
                "mypage" -> { binding.bottomNavi.selectedItemId = R.id.myPageFragment }
                "lounge" -> { binding.bottomNavi.selectedItemId = R.id.loungeFragment }
                "alarm" -> { binding.bottomNavi.selectedItemId = R.id.alarmFragment }
            }
            intent.removeExtra("destination")
        }
    }
}

HomeFragment

• 注入Glide RequestManager
• 在MainActivity布局中
• 下面的代码HouseContentAction是Interface

import androidx.fragment.app.viewModels

@AndroidEntryPoint
class HomeFragment: Fragment(), HouseContentAction {
    private var _binding: FragmentMainHomeBinding? = null
    private val binding get() = _binding!!
    private val viewModel: HomeViewModel by viewModels()
    @Inject lateinit var glide: RequestManager

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentMainHomeBinding.inflate(layoutInflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        ...
        setUpToolBar()
    }

    override fun onDestroyView() {
        super.onDestroyView()
        _binding = null
    }

    private fun setUpToolBar() {
        (requireActivity() as AppCompatActivity).setSupportActionBar(binding.homeToolbar)
        (requireActivity() as AppCompatActivity).supportActionBar?.setIcon(AppCompatResources.getDrawable(requireContext(), R.drawable.head_logo))
        (requireActivity() as AppCompatActivity).supportActionBar?.title = ""
    }

LoungeFragment

@AndroidEntryPoint
class LoungeFragment:Fragment(), LoungeContentActions, LoungeActions {
    private var _binding: FragmentMainLoungeBinding? = null
    private val binding get() = _binding!!
    private val viewModel: LoungeViewModel by viewModels()
    @Inject lateinit var glide: RequestManager

    override fun onCreateView() {
        //same as above
    }

    override fun onViewCreated() {
        //same as above, but no toolbar setting
    }

    override fun onDestroyView() {
        //same as above
    }

MyPageFragment

与上面相同，但是没有工具栏

AlarmFragment

与上面相同，但没有工具栏设置并且没有注入滑行