当我试图对底部导航进行意图时，我得到了这个错误

Question

下面是我的代码：

class Principal : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_principal2)
    val navView: BottomNavigationView = 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.
    val appBarConfiguration = AppBarConfiguration(
        setOf(
            R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications
        )
    )

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

java.lang.runtimeException：无法启动活动ComponentInfo{com.example.auditoriamedica/com.example.auditoriamedica.views.principal}:java.lang.IllegalStateException:findViewById(r.id.nav_view)在Android.app.activitythread.performLaunchActivit(activitythread.java:2665)在1477）在Android.os.handler.dispatchMessage（handler.java：102）在Android.os.looper.loop（looper.java：154）在Android.app.activitythread.main（activitythread.java：6119）在java.lang.reflect.Method.invoke（原生方法）在com.android.internal.os.zygoteinit$methodandArgscaller.run(zygoteinit.java:776)在在com.example.auditoriamedica.views.principal.on不能为空在Android.app.activity.performCreate（activity.java:6679)在Android.app.instrumentation.CallActivityonCreate（instrumentation.java:1118)在Android.app.activitythread.performLaunchActivity（activitythread.java:2618)在Android.app.activitythread.handleLaunchActivity（activitythread.java:2726) 在Android.app.activitythread.-Wrap12(activitythread.java) 在Android.app.activitythread$h.handleMessage(activitythread.java:1477) 在Android.os.handler.DispatchMessage(Handler.java:102) 在Android.os.looper.loop(looper.java:154) 在Android.app.activitythread.main(activitythread.java:6119) 在java.lang.reflect.Method.invoke（本机方法） 在com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:886) 在com.android.internal.os.zygoteinit.main(zygoteinit.java:776)

Answer 1

我意识到问题是我的应用程序主题是noactionbar。我真的不知道如果我想使用底部导航视图，为什么我必须有一个动作栏。如果有人知道如何在bottomNavigationView中隐藏操作栏，请告诉我！

谢了！