我正在创建一个带有谷歌地图 View 的应用程序，我希望这个应用程序能够检测用户的当前位置，并在 map 上用标记显示纬度和经度，但到目前为止我所能做的就是显示谷歌地图和当前位置的检测没有任何标记显示并且没有任何文本显示纬度和经度

我直到现在才添加标记，因为我不知道将它放在代码中的什么位置以及这样做的最佳做法是什么

谁能帮帮我？？？ 这是代码:

list 文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="in.wptrafficanalyzer.locationgooglemapv2demo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="16" />

    <permission
        android:name="in.wptrafficanalyzer.LocationGoogleMapV2Demo.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-permission android:name="in.wptrafficanalyzer.LocationGoogleMapV2Demo.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="in.wptrafficanalyzer.locationgooglemapv2demo.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="API KEY" />
    </application>

</manifest>

xml文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/tv_location"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.SupportMapFragment" />

</RelativeLayout>

java文件

package in.wptrafficanalyzer.locationgooglemapv2demo;

import android.app.Dialog;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.widget.TextView;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;

public class MainActivity extends FragmentActivity implements LocationListener {

    GoogleMap googleMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Getting Google Play availability status
        int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

        // Showing status
        if(status!=ConnectionResult.SUCCESS){ // Google Play Services are not available

            int requestCode = 10;
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
            dialog.show();

        }else { // Google Play Services are available

            // Getting reference to the SupportMapFragment of activity_main.xml
            SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

            // Getting GoogleMap object from the fragment
            googleMap = fm.getMap();

            // Enabling MyLocation Layer of Google Map
            googleMap.setMyLocationEnabled(true);

            // Getting LocationManager object from System Service LOCATION_SERVICE
            LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

            // Creating a criteria object to retrieve provider
            Criteria criteria = new Criteria();

            // Getting the name of the best provider
            String provider = locationManager.getBestProvider(criteria, true);

            // Getting Current Location
            Location location = locationManager.getLastKnownLocation(provider);

            if(location!=null){
                onLocationChanged(location);
            }
            locationManager.requestLocationUpdates(provider, 20000, 0, this);
        }
    }
    @Override
    public void onLocationChanged(Location location) {

        TextView tvLocation = (TextView) findViewById(R.id.tv_location);

        // Getting latitude of the current location
        double latitude = location.getLatitude();

        // Getting longitude of the current location
        double longitude = location.getLongitude();

        // Creating a LatLng object for the current location
        LatLng latLng = new LatLng(latitude, longitude);

        // Showing the current location in Google Map
        googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        // Zoom in the Google Map
        googleMap.animateCamera(CameraUpdateFactory.zoomTo(15));

        // Setting latitude and longitude in the TextView tv_location
        tvLocation.setText("Latitude:" +  latitude  + ", Longitude:"+ longitude );

    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

最佳答案

首先查看文档here , 它很好地表明了获得用户位置的最佳策略。

就我个人而言，我通常在 map 开始时将标记放置在检索到的位置

Location lastKnownLocation = locationManager.getLastKnownLocation(locationProvider);

然后我开始监听位置更新并移动标记。

这也取决于您的应用目的需要多精确的位置，如果您不需要非常精确的位置但区域足够，也许您可​​以使用 lastKnownLocation .

你可以试试这样的东西

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // Getting Google Play availability status
    int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

    // Showing status
    if(status!=ConnectionResult.SUCCESS){ // Google Play Services are not available

        int requestCode = 10;
        Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
        dialog.show();

    }else { // Google Play Services are available

        // Getting reference to the SupportMapFragment of activity_main.xml
        SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

        // Getting GoogleMap object from the fragment
        googleMap = fm.getMap();

        // Enabling MyLocation Layer of Google Map
        googleMap.setMyLocationEnabled(true);

        // Getting LocationManager object from System Service LOCATION_SERVICE
        LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

        // Creating a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Getting the name of the best provider
        String provider = locationManager.getBestProvider(criteria, true);

        // Getting Current Location
        Location location = locationManager.getLastKnownLocation(provider);

        LocationListener locationListener = new LocationListener() {
          void onLocationChanged(Location location) {
          // redraw the marker when get location update.
          drawMarker(location);
        }

        if(location!=null){
           //PLACE THE INITIAL MARKER              
           drawMarker(location);
        }
        locationManager.requestLocationUpdates(provider, 20000, 0, locationListener);
    }
}

private void drawMarker(Location location){
    // Remove any existing markers on the map
    googleMap.clear();
    LatLng currentPosition = new LatLng(location.getLatitude(),location.getLongitude());
    googleMap.addMarker(new MarkerOptions()
    .position(currentPosition)
    .snippet("Lat:" + location.getLatitude() + "Lng:"+ location.getLongitude())
    .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE))
    .title("ME"));
}

此外，您不需要 Activity 类来 implements LocationListener ，你可以像我上面那样定义一个监听器并注册它

附言我没有编辑器，我的代码可能包含拼写错误

希望这对你有帮助，干杯

关于android + google map api v2 + 当前位置，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16005223/