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Question

问题是我正在尝试获取用户的当前位置并且代码没有给出任何错误，除了代码编译时，它应该执行onLocationChanged方法但它不会执行它。 我还在我的清单文件中设置权限，但我不知道为什么我似乎无法理解问题是什么。请帮忙。

地图活动

这是我的地图活动，我正在尝试将标记设置为当前位置

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text; 
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Gms.Maps;
using Android.Gms.Maps.Model;
using Android.Graphics;
using Android.Locations;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Newtonsoft.Json;

namespace RoutineApp
{
    [Activity(Label = "GoogleMapDirectionsActivity", MainLauncher = true, ScreenOrientation = ScreenOrientation.Portrait, Theme = "@style/Theme.AppCompat.Light.NoActionBar")]
    public class GoogleMapDirectionsActivity : Activity, IOnMapReadyCallback, ILocationListener
    {
        private GoogleMap gMap;
        private MapFragment mapFragment;
        private LocationManager locationManager;
        string locationProvider;
        private MarkerOptions markerOptions;
        private Marker marker;

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.googlemapdirections);

            mapFragment = (MapFragment)FragmentManager.FindFragmentById(Resource.Id.DirectionMap);
            mapFragment.GetMapAsync(this);
            goBtn = FindViewById<Button>(Resource.Id.GoBtn);

            //user location
            IntializeLocationManager();
        }
        private void IntializeLocationManager()
        {
            locationManager = (LocationManager)GetSystemService(LocationService);
            Criteria criteriaForLocationService = new Criteria
            {
                Accuracy = Accuracy.Fine
            };
            IList<string> acceptableLocationProviders = locationManager.GetProviders(criteriaForLocationService, true);
            if (acceptableLocationProviders.Any())
            {
                locationProvider = acceptableLocationProviders.First();
            }
            else
            {
                locationProvider = string.Empty;
            }
            //Log.Debug(TAG, "Using " + locationProvider + ".");
        }
        public void OnMapReady(GoogleMap googleMap)
        {
            gMap = googleMap;
            //mDirectionMap.TrafficEnabled = true;
            gMap.UiSettings.CompassEnabled = true;
            gMap.UiSettings.MyLocationButtonEnabled = true;
            gMap.UiSettings.ZoomControlsEnabled = true;
  OnLocationChanged(locationManager.GetLastKnownLocation(locationProvider));
        }
        protected override void OnResume()
        {
            base.OnResume();
            locationManager.RequestLocationUpdates(locationProvider, 400, 0, this);
        }
        protected override void OnPause()
        {
            base.OnPause();
            locationManager.RemoveUpdates(this);
        }
        public void OnLocationChanged(Location location)
        {

            if (marker != null)
            {
                marker.Remove();
            }
            LatLng latLng = new LatLng(location.Latitude, location.Longitude);
            markerOptions = new MarkerOptions()
                .SetPosition(latLng)
                .SetTitle("My Current Position");
            marker = gMap.AddMarker(markerOptions);
            CameraUpdate camera = CameraUpdateFactory.NewLatLngZoom(latLng, 19);
            gMap.MoveCamera(camera);

        }

        public void OnProviderDisabled(string provider)
        {
            //throw new NotImplementedException();
        }

        public void OnProviderEnabled(string provider)
        {
            //throw new NotImplementedException();
        }

        public void OnStatusChanged(string provider, [GeneratedEnum] Availability status, Bundle extras)
        {
            //throw new NotImplementedException();
        }
}

Xml地图活动

我的地图活动的xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:weightSum="100"
    android:background="@android:color/holo_blue_dark">
    <EditText
        android:id="@+id/SourceTxtBox"
        android:inputType="text"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="center_horizontal"
        android:background="@drawable/edit_text_style"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginBottom="10dp"
        android:hint="Enter Starting Point"
        android:layout_weight="7"
        android:textColorHint="#a3a3a3"
        android:textColor="#000" />
    <EditText
        android:id="@+id/DestinationTxtBox"
        android:inputType="text"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_gravity="center_horizontal"
        android:background="@drawable/edit_text_style"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginBottom="10dp"
        android:hint="Enter Destination"
        android:layout_weight="7"
        android:textColorHint="#a3a3a3"
        android:textColor="#000" />
    <fragment
        android:id="@+id/DirectionMap"
        android:layout_height="0dp"
        android:layout_width="match_parent"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_weight="80" />
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="6"
        android:weightSum="10">
        <Button
            android:id="@+id/GoBtn"
            android:text="Go"
            android:textSize="10dp"
            android:textStyle="bold"
            android:layout_height="wrap_content"
            android:layout_width="20dp"
            android:layout_weight="1" />
    </LinearLayout>
</LinearLayout>

清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="auto" package="com.company.RoutineApp" android:versionCode="1" android:versionName="1">
  <uses-sdk android:minSdkVersion="15" />
  <!-- Google Maps for Android v2 requires OpenGL ES v2 -->
  <uses-feature android:glEsVersion="0x00020000" android:required="true" />

  <!-- We need to be able to download map tiles and access Google Play Services-->
  <uses-permission android:name="android.permission.INTERNET" />

  <!-- Allow the application to access Google web-based services. -->
  <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />

  <!-- Google Maps for Android v2 will cache map tiles on external storage -->
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

  <!-- Google Maps for Android v2 needs this permission so that it may check the connection state as it must download data -->
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

  <!-- Permission to receive remote notifications from Google Play Services -->
  <!-- Notice here that we have the package name of our application as a prefix on the permissions. -->
  <uses-permission android:name="com.company.RoutineApp.permission.MAPS_RECEIVE" />
  <permission android:name="com.company.RoutineApp.permission.MAPS_RECEIVE" android:protectionLevel="signature" />

      <!-- These are optional, but recommended. They will allow Maps to use the My Location provider. -->
      <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
      <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
      <!--<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />  
      <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>--> 
  <application android:label="@string/app_name" android:icon="@drawable/Icon" android:theme="@style/Theme.MyTheme">
    <meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="AIzaSyAGQlTIquLL5yyIr47pI_AA9g1CI-Whh0o" />
    <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />
  </application>
</manifest>

这是我的应用程序的屏幕截图