无法获得SupportMapFragment返回任何东西…似乎总是为空

所以这里是我的代码：克鲁克斯的事情是onMapReady没有被叫，所以我玩弄了

错误

进程：com.example.herbstzu.listview，PID：16963 kotlin.TypeCastException：null不能转换为非空类型com.google.android.gms.maps.SupportMapFragment

XML

..... <LinearLayout android:id="@+id/LayoutInfo" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_marginVertical="10dp" android:orientation="horizontal"> <ImageView android:id="@+id/imagePhone2" android:layout_width="60dp" android:layout_height="60dp" android:layout_gravity="start" android:layout_marginLeft="15dp" android:layout_marginRight="15dp" app:srcCompat="@drawable/ic_exclamation" /> <TextView android:id="@+id/info_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="TextView" android:textColor="#000000" /> </LinearLayout> <fragment class="com.google.android.gms.maps.MapFragment" android:id="@+id/mapF" android:layout_width="match_parent" android:layout_height="200dp"/> </LinearLayout> </ScrollView> 

Kotlin片段类

 import android.os.Bundle import android.support.v4.app.Fragment import android.util.Log import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import com.google.android.gms.maps.model.LatLng import com.google.android.gms.maps.model.MarkerOptions import com.google.android.gms.maps.SupportMapFragment import com.google.android.gms.maps.CameraUpdateFactory import com.google.android.gms.maps.GoogleMap import com.google.android.gms.maps.OnMapReadyCallback class Event_details : Fragment(),OnMapReadyCallback{ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) } override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? { var myView = inflater!!.inflate(R.layout.fragment_event_details, container, false) var mapFragment = activity.fragmentManager.findFragmentById(R.id.mapF) as SupportMapFragment mapFragment.getMapAsync(this) return myView } override fun onMapReady(googleMap: GoogleMap) { Log.d("onMapready","MapReady") val cphbusiness = LatLng(55.770535, 12.511922) googleMap.addMarker(MarkerOptions().position(cphbusiness).title("Her")) googleMap.moveCamera(CameraUpdateFactory.zoomTo(16.0F)) googleMap.moveCamera(CameraUpdateFactory.newLatLng(cphbusiness)) } }// Required empty public constructor 

Answer 1

你正在使用错误的片段管理器。 你需要使用supportFragmentManager

  var mapFragment = activity.supportFragmentManager.findFragmentById(R.id.mapF) as SupportMapFragment