添加 Fragment 后导航抽屉崩溃

如何解决添加 Fragment 后导航抽屉崩溃

嗨，导航抽屉有问题。我使用带有导航抽屉的默认布局来了解如何添加更多内容。我创建了类似这个默认的类。但是这些女巫在开始时正在工作，但我装箱的另一个女巫没有，当我尝试点击这三个“naprawa”、“oc”、“pt”应用程序时崩溃了。在每个fragment....xml我有 tools:context=".ui.<folder>.<...Fragment>" 的片段名称。有人知道哪里有问题吗？我也有这个错误：

    Process: com.example.carplanner,PID: 23240
    kotlin.UninitializedPropertyAccessException: lateinit property naprawaViewModel has not been initialized
        at com.example.carplanner.ui.naprawa.NaprawaFragment.onCreateView(NaprawaFragment.kt:23)
        at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698)
        at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320)
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187)
        at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953)
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849)
        at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

这是代码：

package com.example.carplanner

import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import android.widget.Toast
import com.google.android.material.floatingactionbutton.FloatingActionButton
import com.google.android.material.snackbar.Snackbar
import com.google.android.material.navigation.NavigationView
import androidx.navigation.findNavController
import androidx.navigation.ui.AppBarConfiguration
import androidx.navigation.ui.navigateUp
import androidx.navigation.ui.setupActionBarWithNavController
import androidx.navigation.ui.setupWithNavController
import androidx.drawerlayout.widget.DrawerLayout
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.Toolbar
import android.view.View
import android.content.Intent


class MainActivity : AppCompatActivity() {

    private lateinit var appBarConfiguration: AppBarConfiguration

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val toolbar: Toolbar = findViewById(R.id.toolbar)
        setSupportActionBar(toolbar)

        val fab: FloatingActionButton = findViewById(R.id.fab)
        fab.setOnClickListener { view ->
            Snackbar.make(view,"Replace with your own action",Snackbar.LENGTH_LONG)
                .setAction("Action",null).show()
        }
        val drawerLayout: DrawerLayout = findViewById(R.id.drawer_layout)
        val navView: NavigationView = findViewById(R.id.nav_view)
        val navController = findNavController(R.id.nav_host_fragment)
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        appBarConfiguration = AppBarConfiguration(setOf(

            R.id.nav_home,R.id.nav_paliwo,R.id.nav_naprawa,R.id.nav_wydatki,R.id.nav_oc,R.id.nav_pt),drawerLayout)

        setupActionBarWithNavController(navController,appBarConfiguration)
        navView.setupWithNavController(navController)
    }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        // Inflate the menu; this adds items to the action bar if it is present.
        menuInflater.inflate(R.menu.main,menu)


            return true

    }


    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        val id = item.itemId
        if (id == R.id.btn_settings) {
            val intent = Intent(
                    this,SettingsActivity ::class.java)
            startActivity (intent)
        }else{
            if (id == R.id.btn_about){
                val intent = Intent(
                    this,About ::class.java)
                startActivity (intent)
            }
        }
        return super.onOptionsItemSelected(item)
    }

    override fun onSupportNavigateUp(): Boolean {
        val navController = findNavController(R.id.nav_host_fragment)
        return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
    }
    }

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:showIn="navigation_view">

    <group android:checkableBehavior="single">
        <item
            android:id="@+id/nav_home"
            android:icon="@android:drawable/ic_dialog_dialer"
            android:title="@string/strona_g_wna" />
        <item
            android:id="@+id/nav_paliwo"
            android:icon="@drawable/ic_paliwo"
            android:title="@string/tankowanie" />
        <item
            android:id="@+id/nav_naprawa"
            android:icon="@drawable/ic_naprawa"
            android:title="@string/naprawy" />
        <item
            android:id="@+id/nav_wydatki"
            android:icon="@drawable/ic_wydatki"
            android:title="@string/wydatki" />
        <item
            android:id="@+id/nav_oc"
            android:icon="@drawable/ic_oc"
            android:title="@string/ubezpieczenia" />
        <item
            android:id="@+id/nav_pt"
            android:icon="@android:drawable/stat_notify_error"
            android:title="@string/przegl_d_techniczny" />
    </group>
</menu>

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/mobile_navigation"
    app:startDestination="@+id/nav_home">

    <fragment
        android:id="@+id/nav_home"
        android:name="com.example.carplanner.ui.home.HomeFragment"
        android:label="Strona Główna"
        tools:layout="@layout/fragment_home" />

    <fragment
        android:id="@+id/nav_paliwo"
        android:name="com.example.carplanner.ui.paliwo.PaliwoFragment"
        android:label="Paliwo"
        tools:layout="@layout/fragment_paliwo" />


    <fragment
        android:id="@+id/nav_naprawa"
        android:name="com.example.carplanner.ui.naprawa.NaprawaFragment"
        android:label="Naprawy"
        tools:layout="@layout/fragment_naprawa" />
    <fragment
        android:id="@+id/nav_wydatki"
        android:name="com.example.carplanner.ui.wydatki.WydatkiFragment"
        android:label="Wydatki"
        tools:layout="@layout/fragment_wydatki" />
    <fragment
        android:id="@+id/nav_oc"
        android:name="com.example.carplanner.ui.oc.OcFragment"
        android:label="Ubezpieczenia"
        tools:layout="@layout/fragment_oc" />
    <fragment
        android:id="@+id/nav_pt"
        android:name="com.example.carplanner.ui.pt.PtFragment"
        android:label="Przegląd techniczny"
        tools:layout="@layout/fragment_pt" />

    <fragment
        android:id="@+id/nav_setting"
        android:name="com.example.carplanner.SettingsActivity$SettingsFragment"

        tools:layout="@layout/settings_activity" />

</navigation>

和 NaprawaFragment 代码：

package com.example.carplanner.ui.naprawa
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import com.example.carplanner.R


class NaprawaFragment : Fragment() {

    private lateinit var naprawaViewModel: NaprawaViewModel

    override fun onCreateView(
        inflater: LayoutInflater,container: ViewGroup?,savedInstanceState: Bundle?
    ): View? {
        naprawaViewModel =
            ViewModelProvider(this).get(naprawaViewModel::class.java)
        val root = inflater.inflate(R.layout.fragment_naprawa,container,false)
        val textView: TextView = root.findViewById(R.id.text_naprawa)
        naprawaViewModel.text.observe(viewLifecycleOwner,Observer {
            textView.text = it
        })
        return root
    }
}

以及正常工作的 HomeFragment

package com.example.carplanner.ui.home

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import com.example.carplanner.R

class HomeFragment : Fragment() {

    private lateinit var homeViewModel: HomeViewModel

    override fun onCreateView(
            inflater: LayoutInflater,savedInstanceState: Bundle?
    ): View? {
        homeViewModel =
                ViewModelProvider(this).get(HomeViewModel::class.java)
        val root = inflater.inflate(R.layout.fragment_home,false)
        val textView: TextView = root.findViewById(R.id.text_home)
        homeViewModel.text.observe(viewLifecycleOwner,Observer {
            textView.text = it
        })
        return root
    }
}

添加 Fragment 后导航抽屉崩溃

如何解决添加 Fragment 后导航抽屉崩溃

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