MAPBOX：当我运行应用程序时，地图不会出现，没有错误（在Kotlin-for android-map的片段中开发）

Question

我正在Kotlin为android开发一个应用程序。我正在将Mapbox添加到此应用程序。特别是，我需要在FragmentHome中插入Mapbox的地图。地图需要与其他组件、导航栏和一些按钮交互。

在我插入的活动中

class HostActivity : AppCompatActivity() {
    lateinit var googleSignInClient: GoogleSignInClient
    private lateinit var navController: NavController
    private val mAuth: FirebaseAuth = FirebaseAuth.getInstance()
    private val db: FirebaseFirestore = FirebaseFirestore.getInstance()
    private lateinit var drawerLayout: DrawerLayout
    private lateinit var navViewBinding: DrawerHeaderLayoutBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        setTheme(R.style.AppTheme)
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_host)
        val toolbar = customToolbar
        setSupportActionBar(toolbar)

        val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestIdToken(getString(R.string.default_web_client_id))
            .requestEmail()
            .build()
        googleSignInClient = GoogleSignIn.getClient(this, gso)

        drawerLayout = drawer_layout
        navViewBinding = DrawerHeaderLayoutBinding.inflate(layoutInflater, navView, true)
        val navHost =
            supportFragmentManager.findFragmentById(R.id.navHostFragment) as NavHostFragment
        navController = navHost.navController

        val navInflater = navController.navInflater

        val graph = navInflater.inflate(R.navigation.main_graph)

        navController.addOnDestinationChangedListener { _, destination, _ ->
            if (destination.id == R.id.onBoarding ||
                destination.id == R.id.authFragment ||
                destination.id == R.id.loginFragment ||
                destination.id == R.id.signUpFragment
            ) {
                toolbar.visibility = View.GONE
                drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
            } else {
                toolbar.visibility = View.VISIBLE
                drawerLayout.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
            }
        }
        if (!Prefs.getInstance(this)!!.hasCompletedWalkthrough!!) {
            if (mAuth.currentUser == null) {
                graph.startDestination = R.id.authFragment
            } else {
                getUserData()
                graph.startDestination = R.id.homeFragment
            }
        } else {
            graph.startDestination = R.id.onBoarding

        }
        navController.graph = graph

        NavigationUI.setupActionBarWithNavController(this, navController, drawerLayout)
        navView.setupWithNavController(navController)
        navView.setNavigationItemSelectedListener {
            it.isChecked
            drawerLayout.closeDrawers()
            when (it.itemId) {
                R.id.action_logout -> {
                    MyApplication.currentUser!!.active = false
                    FirestoreUtil.updateUser(MyApplication.currentUser!!) {
                        mAuth.signOut()
                    }
                    googleSignInClient.signOut()
                    MyApplication.currentUser = null
                    navController.navigate(R.id.action_logout)
                }
            }
            true
        }
    }

    private fun getUserData() {

        val ref = db.collection("users").document(mAuth.currentUser!!.uid)

        ref.get().addOnSuccessListener {
            val userInfo = it.toObject(UserModel::class.java)
            navViewBinding.user = userInfo
            MyApplication.currentUser = userInfo
            MyApplication.currentUser!!.active = true
            FirestoreUtil.updateUser(MyApplication.currentUser!!) {
            }
        }.addOnFailureListener {
            val intent = Intent(this, MyApplication::class.java)
            startActivity(intent)
            finish()
        }
    }

    override fun onSupportNavigateUp(): Boolean {
        return NavigationUI.navigateUp(navController, drawerLayout)
    }

}

与HostActivity相关的XML图形部分如下所示：

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout 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/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.instamobile.firebaseStarterKit.ui.activity.host.HostActivity">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appBar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintBottom_toTopOf="@id/navHostFragment"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/customToolbar"
                style="@style/MyToolbarThemeSimple.Base"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize" />

        </com.google.android.material.appbar.AppBarLayout>

        <androidx.fragment.app.FragmentContainerView
            android:id="@+id/navHostFragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:defaultNavHost="true"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="1.0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/appBar"
            app:navGraph="@navigation/main_graph" />

    </androidx.constraintlayout.widget.ConstraintLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@+id/navView"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/drawer_header_layout"
        app:itemIconTint="@color/colorPrimary"
        app:menu="@menu/drawer_menu" />
</androidx.drawerlayout.widget.DrawerLayout>

在HomeFragment中，我只放置了地图和导航栏，如以下代码所示：

class HomeFragment : Fragment() {
    private var mapView: MapView? = null

    @Nullable
    override fun onCreateView(
        inflater: LayoutInflater,
        @Nullable container: ViewGroup?,
        @Nullable savedInstanceState: Bundle?
    ): View? {
        Mapbox.getInstance(
            context!!.applicationContext,
            "******KEY******"
        )
        val view: View = inflater.inflate(R.layout.fragment_home, container, false)
        mapView = view.findViewById<View>(R.id.mapView) as MapView
        mapView!!.onCreate(savedInstanceState)
        return view
    }

    override fun onStart() {
        super.onStart()
        mapView!!.onStart()
    }

    override fun onResume() {
        super.onResume()
        mapView!!.onResume()
    }

    override fun onPause() {
        super.onPause()
        mapView!!.onPause()
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        mapView!!.onSaveInstanceState(outState)
    }

    override fun onLowMemory() {
        super.onLowMemory()
        mapView!!.onLowMemory()
    }

    override fun onDestroyView() {
        super.onDestroyView()
        mapView!!.onDestroy()
    }
}

最后，与HomeFragment图形部分相关的XML代码如下：

<?xml version="1.0" encoding="utf-8"?>
<layout 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">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".ui.fragment.home.HomeFragment">

        <com.mapbox.mapboxsdk.maps.MapView
            android:id="@+id/mapView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginBottom="60dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="1.0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">

            <com.google.android.material.floatingactionbutton.FloatingActionButton
                android:id="@+id/floatingActionButton"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="5dp"
                android:layout_marginBottom="5dp"
                android:layout_gravity="bottom|right"
                android:clickable="true"
                android:focusable="true"
                app:backgroundTint="#4CAF50"
                app:srcCompat="@drawable/ic_navigation_white_24dp"
                tools:ignore="ContentDescription,MissingConstraints,RtlHardcoded,VectorDrawableCompat" />

            <com.google.android.material.floatingactionbutton.FloatingActionButton
                android:id="@+id/floatingActionButton2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginEnd="5dp"
                android:layout_marginBottom="100dp"
                android:layout_gravity="right|bottom"
                android:clickable="true"
                android:focusable="true"
                app:backgroundTint="#4CAF50"
                app:srcCompat="@drawable/ic_taxi"
                tools:ignore="ContentDescription,DuplicateIds,MissingConstraints,RtlHardcoded,VectorDrawableCompat" />

            <com.google.android.material.floatingactionbutton.FloatingActionButton
                android:id="@+id/floatingActionButton3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="5dp"
                android:layout_marginTop="5dp"
                android:layout_gravity="top|left"
                android:clickable="true"
                android:focusable="true"
                app:backgroundTint="#4CAF50"
                app:srcCompat="@drawable/ic_search"
                tools:ignore="ContentDescription,DuplicateIds,MissingConstraints,RtlHardcoded,VectorDrawableCompat" />

            <com.google.android.material.floatingactionbutton.FloatingActionButton
                android:id="@+id/floatingActionButton4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="5dp"
                android:layout_marginBottom="25dp"
                android:layout_gravity="bottom|left"
                android:clickable="true"
                android:focusable="true"
                app:backgroundTint="#4CAF50"
                app:srcCompat="@drawable/ic_filter"
                tools:ignore="ContentDescription,DuplicateIds,MissingConstraints,RtlHardcoded,VectorDrawableCompat" />


        </com.mapbox.mapboxsdk.maps.MapView>

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottom_navigation"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/mapView"
            app:menu="@menu/bottom_navigation_menu"
            tools:ignore="MissingConstraints" />
    </androidx.constraintlayout.widget.ConstraintLayout>

</layout>

代码将运行，没有错误，但不会显示映射。我们做得好吗？我们在代码中找不到任何错误。你能？

非常感谢。最好的

Answer 1

我也有同样的问题。我通过调用getMapAsync来解决它。你必须在返回视图之前添加这段代码。

mapView!!.getMapAsync { mapboxMap ->
       mapboxMap.setStyle(Style.MAPBOX_STREETS) {
    
       }