使用 Kotlin 片段时不必要的数据重复

帮助我理解为什么按下手机的“返回”按钮时数据重复，即我们有一个12个字段的列表，当从主片段移动到子片段再返回时，列表已经有24个字段，我们重复相同的步骤和列表已经是36个字段，等等现在也许记忆不会结束。

英雄碎片

 class HeroesFragment : Fragment() {

    private var mBinding: FragmentHeroesBinding? = null

    private lateinit var mAllInfoApex: HeroesViewModel

    private lateinit var mHeroesAdapter: HeroesAdapter

 override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setHasOptionsMenu(true)

    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
            mBinding = FragmentHeroesBinding.inflate(inflater, container, false)
            return mBinding!!.root
    }
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        mAllInfoApex =
            ViewModelProvider(this).get(HeroesViewModel::class.java)

        mAllInfoApex.getAllInfoApexFromAPI(Constants.API_PLAYER_VALUE)

        mBinding?.rvHeroList?.layoutManager = GridLayoutManager(requireActivity(), 2)

        mHeroesAdapter = HeroesAdapter(this@HeroesFragment)

        mBinding?.rvHeroList?.adapter = mHeroesAdapter

        InfoApexViewModelObserver()
    }
        fun heroesDetails(legends: Heroes){
        findNavController().navigate(HeroesFragmentDirections.actionAllHeroesToHeroesDetails(legends))
    }

    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        inflater.inflate(R.menu.menu_profile, menu)
        super.onCreateOptionsMenu(menu, inflater)
    }
        override fun onDestroy() {
        super.onDestroy()
        mBinding = null
    }
}

详情英雄片段

class DetailsHeroesFragment : Fragment() {

    private var mBinding: FragmentDetailsHeroesBinding? = null

    //private val hero : ArrayList<AllHeroes.Data>? = null


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

    }

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

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        val args: DetailsHeroesFragmentArgs by navArgs()

        Glide.with(this)
            .load(args.heroesDetails.data.ImgAssets.banner)
            .into(mBinding!!.ivHeroesDetails)

        mBinding!!.tvHeroesName.text = args.heroesDetails.name

        args.heroesDetails.data.let { values ->
            when {
                values.data.isNullOrEmpty() -> {
                    mBinding!!.tvDataName.text = "NOT DATA"

                    mBinding!!.tvDataValue.visibility = View.INVISIBLE
                    mBinding!!.tvDataName2.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue2.visibility = View.INVISIBLE
                    mBinding!!.tvDataName3.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue3.visibility = View.INVISIBLE
                    mBinding!!.tvDataName4.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue4.visibility = View.INVISIBLE

                    Log.i("Heroes test", "test")
                }
  else -> {
                    mBinding!!.tvDataName.visibility = View.INVISIBLE

                    mBinding!!.tvDataValue.visibility = View.INVISIBLE
                    mBinding!!.tvDataName2.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue2.visibility = View.INVISIBLE
                    mBinding!!.tvDataName3.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue3.visibility = View.INVISIBLE
                    mBinding!!.tvDataName4.visibility = View.INVISIBLE
                    mBinding!!.tvDataValue4.visibility = View.INVISIBLE
                }
            }
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        mBinding = null
    }
}

主要活动

class MainActivity : AppCompatActivity() {

    private lateinit var mBinding: ActivityMainBinding
    private lateinit var mNavController: NavController


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        mBinding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(mBinding.root)

        mNavController = findNavController(R.id.nav_host_fragment_activity_main)
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        val appBarConfiguration = AppBarConfiguration(
            setOf(
                R.id.navigation_all_heroes,
                R.id.navigation_match_history,
                R.id.navigation_funny_videos
            )
        )
        setupActionBarWithNavController(mNavController, appBarConfiguration)
        mBinding.navView.setupWithNavController(mNavController)

    }
    override fun onSupportNavigateUp(): Boolean {
        return NavigationUI.navigateUp(mNavController, null)
    }    
}

也就是说，当我从DetailsHeroesFragment返回到HeroesFragment时，会在现有数据中添加一列完全相同的数据，如何解决这个问题？或者我在哪里错过了什么？在日志中，我看到数据是如何创建 2 次的，然后在转换期间又是 +2 次，等等。

视图模型

class HeroesViewModel: ViewModel() {

    private val allInfoApexAPIService = AllInfoApexAPIService()

    private val compositeDisposable = CompositeDisposable()

    val loadAllInfoApex = MutableLiveData<Boolean>()
    val allInfoApexResponse = MutableLiveData<AllHeroes.Heroes>()
    val allInfoApexLoadingError = MutableLiveData<Boolean>()

    fun getAllInfoApexFromAPI(username: String){
        loadAllInfoApex.value = true

        compositeDisposable.add(
            allInfoApexAPIService.getAllInfoApexTracker(player = username)
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribeWith(object: DisposableSingleObserver<AllHeroes.Heroes>(){
                    override fun onSuccess(value: AllHeroes.Heroes) {
                        loadAllInfoApex.value = false
                        allInfoApexResponse.value = value
                        allInfoApexLoadingError.value = false

                    }

                    override fun onError(e: Throwable) {
                        loadAllInfoApex.value = false
                        allInfoApexLoadingError.value = true
                        e.printStackTrace()
                    }

                })
        )
    }
}