谷歌地图安卓API v2和当前位置

我正在尝试使用新的谷歌地图Android api v2,我正在为Android 2.3.3或更高版本开发一个应用程序。这是一个非常简单的应用程序:它获取用户的当前位置(使用GPS或网络信号),它使用方向api从db获取POI,它将用户驱动到POI。

我的问题是获取用户当前位置。感谢这篇文章 如何在谷歌地图Android API v2中获取当前位置?我了解到我无法使用新的谷歌API更新当前位置。另一个问题是,我可以使用来设置我的位置,但我不能用来知道用户在哪里。GoogleMap setMyLocationEnabled(boolean enabled)getMyLocation()

我使用本指南 http://www.vogella.com/articles/AndroidLocationAPI/article.html#maps_mylocation 来获取我的位置,并且我试图在我的活动内部集成以绘制用户位置。

这是我的代码:

清单

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

    <uses-permission android:name="it.mappe.permission.MAPS_RECEIVE" />

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="16" />

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

    <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" >

         <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="MYGMAPSKEY" />
        <activity
            android:name="it.mappe.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>
    </application>

</manifest>

主要活动

package it.mappe;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;

import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v4.app.FragmentActivity;
import android.widget.Toast;

public class MainActivity extends FragmentActivity implements LocationListener {
    private GoogleMap map;
    private static final LatLng ROMA = new LatLng(42.093230818037,11.7971813678741);
    private LocationManager locationManager;
    private String provider;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();

        LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
        boolean enabledGPS = service
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
        boolean enabledWiFi = service
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        // Check if enabled and if not send user to the GSP settings
        // Better solution would be to display a dialog and suggesting to 
        // go to the settings
        if (!enabledGPS) {
            Toast.makeText(this, "GPS signal not found", Toast.LENGTH_LONG).show();
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            startActivity(intent);
        }

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        // Define the criteria how to select the locatioin provider -> use
        // default
        Criteria criteria = new Criteria();
        provider = locationManager.getBestProvider(criteria, false);
        Location location = locationManager.getLastKnownLocation(provider);

        // Initialize the location fields
        if (location != null) {
            Toast.makeText(this, "Selected Provider " + provider,
                    Toast.LENGTH_SHORT).show();
            onLocationChanged(location);
        } else {

            //do something
        }

    }

    /* Request updates at startup */
    @Override
    protected void onResume() {
        super.onResume();
        locationManager.requestLocationUpdates(provider, 400, 1, this);
    }

    /* Remove the locationlistener updates when Activity is paused */
    @Override
    protected void onPause() {
        super.onPause();
        locationManager.removeUpdates(this);
    }

    @Override
    public void onLocationChanged(Location location) {
        double lat =  location.getLatitude();
        double lng = location.getLongitude();
        Toast.makeText(this, "Location " + lat+","+lng,
                Toast.LENGTH_LONG).show();
        LatLng coordinate = new LatLng(lat, lng);
        Toast.makeText(this, "Location " + coordinate.latitude+","+coordinate.longitude,
                Toast.LENGTH_LONG).show();
        Marker startPerc = map.addMarker(new MarkerOptions()
        .position(coordinate)
        .title("Start")
        .snippet("Inizio del percorso")
        .icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
    }


    @Override
    public void onProviderDisabled(String provider) {
        Toast.makeText(this, "Enabled new provider " + provider,
                Toast.LENGTH_SHORT).show();

    }


    @Override
    public void onProviderEnabled(String provider) {
        Toast.makeText(this, "Disabled provider " + provider,
                Toast.LENGTH_SHORT).show();

    }


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

    }

}

主布局

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    class="com.google.android.gms.maps.SupportMapFragment" />

它工作但不是那么好,正如你在图片中看到的那样,每年都有一个新的位置,它增加了一个新的标记(我认为是覆盖层...我从不使用旧的谷歌地图api)。enter image description here

如何只显示一个标记?

此外,在我的地图上,我还需要显示POI的标记,所以我认为这不是一个好的解决方案,将所有标记都降级并在地图上重新绘制。还有另一种获取用户当前位置的最佳方法,每时每刻更新它只显示一个自定义标记?!


答案 1

您可以调用以仅删除此标记。startPerc.remove();

从这里


答案 2

为什么不直接使用移动标记,而不是继续添加和删除...startPerc.setPosition


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