java.lang.ClassCastException:不能将com.here.android.mpa.mapping.MapView强制转换为com.here.android.mpa.mapping.AndroidXMapFragment

Question

嗨，我正在使用android的here SDK，我一直收到这个错误，我的项目有一个导航抽屉，我正在尝试用here SDK在其中一个片段中创建一个地图。这是我的XML和Kotlin代码，以及错误my error：

java.lang.ClassCastException: com.here.android.mpa.mapping.MapView cannot be cast to com.here.android.mpa.mapping.AndroidXMapFragment at com.example.pplin_mobilite.ui.Passager.PassagerFragment.onActivityCreated(PassagerFragment.kt:22) at androidx.fragment.app.Fragment.performActivityCreated(Fragment.java:2717) at androidx.fragment.app.FragmentStateManager.activityCreated(FragmentStateManager.java:346) at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1188) 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$4.run(FragmentManager.java:413) at android.os.Handler.handleCallback(Handler.java:873) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6758) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:497) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:912)

我的kotlin类：

class PassagerFragment : Fragment() {

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

    // Search for the Map Fragment
    val mapFragment = map_frag as AndroidXMapFragment
    // initialize the Map Fragment and
    // retrieve the map that is associated to the fragment
    mapFragment.init { error ->
        if (error == OnEngineInitListener.Error.NONE) {
            // now the map is ready to be used
            mapFragment.map
            // ...
        } else {
            println("ERROR: Cannot initialize AndroidXMapFragment")
        }
    }
}

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    return inflater.inflate(R.layout.fragment_notifications,container,false)
}

}

和我的xml：

 <fragment
    class="com.here.android.mpa.mapping.AndroidXMapFragment"
    android:id="@+id/map_frag"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"

    />

Answer 1

如果您正在使用此处的 documentation中的片段，并且将其放入另一个片段中，则应使用：

val mapfragment = childFragmentManager.findFragmentById(R.id.mapfragment) as AndroidXMapFragment

然后找到片段而不是视图(因为它不是视图)，因为如果检查mapfragment，它已经扩展了Fragment()

Answer 2

尝试使用supportFragmentManager：

val mapfragment = supportFragmentManager.findFragmentById(R.id.map_frag) as AndroidXMapFragment?