Question

我想获得Android 2.2中的位置，我已经添加了Google gms播放服务库。我可以设置requestLocationUpdates和getLastKnownLocation，但该位置为空。

日志仅打印03-10 01:23:13.720 27437-27437/? V/GPSTracker provider﹕ gps 03-10 01:23:13.720 27437-27437/? V/GPSTracker﹕ requestLocationUpdates 03-10 01:23:13.720 27437-27437/? V/GPSTracker﹕ getLastKnownLocation。纬度和经度没有表现出来。

package com.example.testlocation;

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
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.os.IBinder;
import android.provider.Settings;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {

    private Context mContext;
    // flag for GPS status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS status
    boolean canGetLocation = false;

    Location location; // location
    double latitude; // latitude
    double longitude; // longitude
    String provider = "";
    float accuracy = 0;

    // Declaring a Location Manager
    protected LocationManager locationManager;

    public GPSTracker() {

    }

    public GPSTracker(Context context) {
        this.mContext = context;
        getLocation();
    }

    public Location getLocation() {
        try {
            locationManager = (LocationManager) mContext
                    .getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

            // getting network status
            isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                // no network provider is enabled
            } else {
                this.canGetLocation = true;
                Criteria criteria = new Criteria();
                provider = locationManager.getBestProvider(criteria, true);
                if (provider != null) {
                    locationManager.requestLocationUpdates(provider,30000,10, this);
                    Log.v("GPSTracker", "requestLocationUpdates");
                }
                if (locationManager != null && provider != null) {
                    location = locationManager.getLastKnownLocation(provider);
                    Log.v("GPSTracker", "getLastKnownLocation");
                    if (location != null) {
                        accuracy = location.getAccuracy();
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                        Log.v("GPSTracker", latitude+", "+longitude);
                    }
                }

            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }

    /**
     * Stop using GPS listener
     * Calling this function will stop using GPS in your app
     * */
    public void stopUsingGPS(){
        if(locationManager != null){
            locationManager.removeUpdates(GPSTracker.this);
        }
    }

    /**
     * Function to get latitude
     * */
    public double getLatitude(){
        if(location != null){
            latitude = location.getLatitude();
        }

        // return latitude
        return latitude;
    }

    /**
     * Function to get longitude
     * */
    public double getLongitude(){
        if(location != null){
            longitude = location.getLongitude();
        }

        // return longitude
        return longitude;
    }

    /**
     * Function to check GPS/wifi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }


    @Override
    public void onLocationChanged(Location location) {
        this.location = location;
        getLatitude();
        getLongitude();
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    }

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    public String getProvider(){
        return provider;
    }

    public float getAccuracy (){
        return accuracy;
    }

}

MainActivity.java

public class MainActivity extends ActionBarActivity {

    private TextView tvLat, tvLong, tvProvider, tvAccuracy;
    private Button btnRefresh;
    private double latitude, longitude;
    private GPSTracker gps;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tvProvider = (TextView)findViewById(R.id.tvProvider);
        tvAccuracy = (TextView)findViewById(R.id.tvAccuracy);
        tvLat = (TextView)findViewById(R.id.tvLat);
        tvLong = (TextView)findViewById(R.id.tvLong);
        btnRefresh = (Button)findViewById(R.id.btnRefresh);

        gps = new GPSTracker(this);
        latitude = gps.getLatitude();
        longitude = gps.getLongitude();
        tvProvider.setText("Provider: "+gps.getProvider());
        tvAccuracy.setText("Accuracy: "+gps.getAccuracy());
        tvLat.setText("Latitude: "+latitude);
        tvLong.setText("Longitude: "+longitude);

        btnRefresh.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                latitude = gps.getLatitude();
                longitude = gps.getLongitude();
                tvProvider.setText("Provider: "+gps.getProvider());
                tvAccuracy.setText("Accuracy: "+gps.getAccuracy());
                tvLat.setText("Latitude: "+latitude);
                tvLong.setText("Longitude: "+longitude);
            }
        });
    }

}

摇篮

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:21.0.3'
    compile 'com.google.android.gms:play-services:6.5.87'
}

清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.testlocation" >
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <uses-sdk tools:overrideLibrary="com.google.android.gms"/>
    <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.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity
            android:name=".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>

        <service android:name=".GPSTracker" />
    </application>

</manifest>

Answer 1

您正在设置位置并立即获取位置！这没有足够的时间来获取位置，因此您将获得null。你应该做的是实现locationlistener并在那里（onLocationChanged方法），获取并显示位置

您将GPS代码放入服务中，实际上您没有剩余的服务代码，而您甚至没有启动它。我认为你是Android的新手，你已经尝试了先进的领域。所以这是我给你的建议

而不是

public class GPSTracker extends Service implements LocationListener {

DO

public class GPSTracker  implements LocationListener {

同样在GPSTracker中执行以下操作 public void init（）{ 尝试{ locationManager =（LocationManager）mContext .getSystemService（LOCATION_SERVICE）;

        // getting GPS status
        isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            Criteria criteria = new Criteria();
            provider = locationManager.getBestProvider(criteria, true);
            if (provider != null) {
                locationManager.requestLocationUpdates(provider,30000,10, this);
                Log.v("GPSTracker", "requestLocationUpdates");
            }else{
             Log.v("GPSTracker", "ERROR1");
            }

        }else{

       Log.v("GPSTracker", "ERROR2");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }


}

public Location getLocation() {

        return location;
    }

在您的MainActivity.java中，在实例化之后执行gps.init（）。运行它并查看它是否运行并观察输出是否有错误。

另外，不要忘记从xml中删除服务

无法获得位置 - Android

1 个答案: