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java - 放置在片段中时，此处不显示地图

问题描述

我正在尝试在我的应用程序中使用 HERE 地图。但是，尝试在片段视图中查看地图时，我似乎遇到了一些困难。当地图显示在我的主要活动中时，没有出现此问题。

我以这些例子为基础。在活动中使用时效果很好。

我已查看此线程无济于事。

您可能会发现我的代码的简化版本应该查看下面的地图：

主要活动类：


package com.example.heremapapplication;
import android.Manifest;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.here.android.mpa.common.ApplicationContext;

public class MainActivity extends AppCompatActivity {

    MapFragmentView mapFragmentView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
        }
        if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, 1);
        }

        initiateMap();
    }

    public void initiateMap() {
        //Start map
        mapFragmentView = new MapFragmentView();
        mapFragmentView.setM_activity(this);
        ApplicationContext applicationContext = new ApplicationContext(getApplicationContext());
        mapFragmentView.initMapFragment(applicationContext, this);
        getSupportFragmentManager().beginTransaction().replace(R.id.frameLayoutMapView, mapFragmentView).commit();

    }
}

MapFragmentView 片段：


package com.example.heremapapplication;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.InflateException;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.here.android.mpa.common.ApplicationContext;
import com.here.android.mpa.common.GeoCoordinate;
import com.here.android.mpa.common.MapEngine;
import com.here.android.mpa.common.OnEngineInitListener;
import com.here.android.mpa.common.PositioningManager;
import com.here.android.mpa.mapping.Map;
import com.here.android.mpa.mapping.MapView;
import java.io.File;


public class MapFragmentView extends Fragment {

    private AppCompatActivity m_activity;
    private PositioningManager positioningManager;
    private MapEngine mapEngine = MapEngine.getInstance();
    private MapView mapView;
    private static View v;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        if (v != null) {
            ViewGroup parent = (ViewGroup) v.getParent();
            if (parent != null)
                parent.removeView(v);

        }
        try {
            v = inflater.inflate(R.layout.map_fragment, container, false);
        } catch (InflateException e) {
            /* map is already there, just return view as it is */
        }
        return v;

    }


    public MapFragmentView() {
    }

    private Map map;

    public void initMapFragment(ApplicationContext applicationContext, Context context) {
        /* Locate the mapFragment UI element */
        mapView = new MapView(context);

        // Set path of isolated disk cache
        String diskCacheRoot = Environment.getExternalStorageDirectory().getPath()
                + File.separator + ".isolated-here-maps";
        // Retrieve intent name from manifest
        String intentName = "";
        try {
            ApplicationInfo ai = m_activity.getPackageManager().getApplicationInfo(m_activity.getPackageName(), PackageManager.GET_META_DATA);
            Bundle bundle = ai.metaData;
            intentName = bundle.getString("INTENT_NAME");
        } catch (PackageManager.NameNotFoundException e) {
            Log.e(this.getClass().toString(), "Failed to find intent name, NameNotFound: " + e.getMessage());
        }
        boolean success = com.here.android.mpa.common.MapSettings.setIsolatedDiskCacheRootPath(diskCacheRoot, intentName);
        if (!success) {
            // Setting the isolated disk cache was not successful, please check if the path is valid and
            // ensure that it does not match the default location
            // (getExternalStorageDirectory()/.here-maps).
            // Also, ensure the provided intent name does not match the default intent name.
        } else {

            if (mapView != null) {
                System.out.println("hop buraya girildi!");

                /* Initialize the SupportMapFragment, results will be given via the called back. m_mapFragment.init(context,new OnEngineInitListener() */
                mapEngine.init(applicationContext, new OnEngineInitListener() {
                    @Override
                    public void onEngineInitializationCompleted(OnEngineInitListener.Error error) {
                        if (error == Error.NONE) {
                            positioningManager = PositioningManager.getInstance();
                            positioningManager.start(PositioningManager.LocationMethod.GPS_NETWORK_INDOOR);
                            map = mapView.getMap();
                            GeoCoordinate myCurrentPosition = positioningManager.getPosition().getCoordinate();
                        } else {
                            Toast.makeText(m_activity,
                                    "ERROR: Cannot initialize Map with error " + error,
                                    Toast.LENGTH_LONG).show();
                        }
                    }
                });
            }
        }
    }

    public void setM_activity(AppCompatActivity m_activity) {
        this.m_activity = m_activity;
    }


}

活动主.xml：


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@+id/frameLayoutMapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        app:layout_constraintTop_toTopOf="parent">

    </FrameLayout>
</RelativeLayout>

map_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mapFragment"
    android:name="com.here.android.mpa.mapping.MapFragment"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

运行程序后，我们应该能够在屏幕上查看 HEREmap。然而它并没有出现。我们看到一个白色的屏幕。如果我们在后台发送应用程序，屏幕会变黑。

非常感谢！

标签： javaandroidhere-api

解决方案

我找到了一个干净且简单的解决方案，可以在片段中使用此处的地图，事实上，在我的项目中，我默认使用导航抽屉活动，我使用其中一个片段来放置我的地图，我共享代码，因为它花费了我努力抽象它

class GalleryFragment : Fragment() {

    private lateinit var galleryViewModel: GalleryViewModel

    /**
     * permissions request code
     */
    private val REQUEST_CODE_ASK_PERMISSIONS = 1

    /**
     * Permissions that need to be explicitly requested from end user.
     */
    private val REQUIRED_SDK_PERMISSIONS = arrayOf<String>(
        Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.WRITE_EXTERNAL_STORAGE
    )
    private var map: Map? = null

    // map fragment embedded in this activity
    private lateinit var mapFragment: AndroidXMapFragment
    private var initialitation : Boolean = false

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        checkPermissions()
        galleryViewModel =
            ViewModelProviders.of(this).get(GalleryViewModel::class.java)
        val root = inflater.inflate(R.layout.fragment_gallery, container, false)

        if(initialitation){
            mapFragment = childFragmentManager.findFragmentById(R.id.mapfragment) as AndroidXMapFragment
            mapFragment.init {
                if(it == OnEngineInitListener.Error.NONE){
                    map = mapFragment.map
                    map!!.setCenter(
                        GeoCoordinate(49.196261, -123.004773, 0.0),
                        Map.Animation.NONE)
                    map!!.zoomLevel = (map!!.maxZoomLevel + map!!.minZoomLevel) / 2
                }else{
                    Log.e(TAG,"Error al inicializar el mapa")
                }
            }
        }

        return root
    }


    /**
     * Checks the dynamically-controlled permissions and requests missing permissions from end user.
     */
    protected fun checkPermissions() {
        val missingPermissions: MutableList<String> = ArrayList()
        // check all required dynamic permissions
        for (permission in REQUIRED_SDK_PERMISSIONS) {
            val result = ContextCompat.checkSelfPermission(requireActivity(), permission)
            if (result != PackageManager.PERMISSION_GRANTED) {
                missingPermissions.add(permission)
            }
        }
        if (!missingPermissions.isEmpty()) {
            // request all missing permissions
            val permissions = missingPermissions
                .toTypedArray()
            ActivityCompat.requestPermissions(
                requireActivity(),
                permissions,
                REQUEST_CODE_ASK_PERMISSIONS
            )
        } else {
            val grantResults = IntArray(REQUIRED_SDK_PERMISSIONS.size)
            Arrays.fill(grantResults, PackageManager.PERMISSION_GRANTED)
            onRequestPermissionsResult(
                REQUEST_CODE_ASK_PERMISSIONS, REQUIRED_SDK_PERMISSIONS,
                grantResults
            )
        }
    }

    override fun onRequestPermissionsResult(
        requestCode: Int, permissions: Array<String>,
        grantResults: IntArray
    ) {
        when (requestCode) {
            REQUEST_CODE_ASK_PERMISSIONS -> {
                var index = permissions.size - 1
                while (index >= 0) {
                    if (grantResults[index] != PackageManager.PERMISSION_GRANTED) {
                        // exit the app if one permission is not granted
                        Toast.makeText(
                            activity, "Required permission '" + permissions[index]
                                    + "' not granted, exiting", Toast.LENGTH_LONG
                        ).show()
                        requireActivity().finish()
                        return
                    }
                    --index
                }
                // all permissions were granted
                initialitation = true
            }
        }
    }
}

这是我使用的 XML 片段

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.gallery.GalleryFragment">

    <fragment
        android:id="@+id/mapfragment"
        class="com.here.android.mpa.mapping.AndroidXMapFragment"
        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" />
</androidx.constraintlayout.widget.ConstraintLayout>

我希望它可以帮助你或遇到同样问题的人

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