我需要通过GPS程序获得我的当前位置。 我怎样才能做到呢?


当前回答

我已经创建了一个小的应用程序,一步一步的描述,以获得当前位置的GPS坐标。

完整的示例源代码是在获取当前位置坐标,城市名称-在Android。


看看它是如何工作的:

All we need to do is add this permission in the manifest file: <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> And create a LocationManager instance like this: LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); Check if GPS is enabled or not. And then implement LocationListener and get coordinates: LocationListener locationListener = new MyLocationListener(); locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 5000, 10, locationListener); Here is the sample code to do so


/*---------- Listener class to get coordinates ------------- */
private class MyLocationListener implements LocationListener {

    @Override
    public void onLocationChanged(Location loc) {
        editLocation.setText("");
        pb.setVisibility(View.INVISIBLE);
        Toast.makeText(
                getBaseContext(),
                "Location changed: Lat: " + loc.getLatitude() + " Lng: "
                    + loc.getLongitude(), Toast.LENGTH_SHORT).show();
        String longitude = "Longitude: " + loc.getLongitude();
        Log.v(TAG, longitude);
        String latitude = "Latitude: " + loc.getLatitude();
        Log.v(TAG, latitude);

        /*------- To get city name from coordinates -------- */
        String cityName = null;
        Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
        List<Address> addresses;
        try {
            addresses = gcd.getFromLocation(loc.getLatitude(),
                    loc.getLongitude(), 1);
            if (addresses.size() > 0) {
                System.out.println(addresses.get(0).getLocality());
                cityName = addresses.get(0).getLocality();
            }
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        String s = longitude + "\n" + latitude + "\n\nMy Current City is: "
            + cityName;
        editLocation.setText(s);
    }

    @Override
    public void onProviderDisabled(String provider) {}

    @Override
    public void onProviderEnabled(String provider) {}

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

其他回答

LocationManager是一个类,它提供内置方法来获取最后知道的位置

步骤1:如下所示创建LocationManager对象

导航(导航);

步骤2:添加标准

*Criteria is use for setting accuracy*

Criteria criteria = new Criteria();
int currentapiVersion = android.os.Build.VERSION.SDK_INT;

if (currentapiVersion >= android.os.Build.VERSION_CODES.HONEYCOMB) {

    criteria.setSpeedAccuracy(Criteria.ACCURACY_HIGH);
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setAltitudeRequired(true);
    criteria.setBearingRequired(true);
    criteria.setSpeedRequired(true);

}

步骤3:获取可用的提供商

有两种类型的供应商GPS和网络

 String provider = locationManager.getBestProvider(criteria, true);

第四步:了解最后知道的地点

Location location = locationManager.getLastKnownLocation(provider);

第五步:获取经纬度

如果location对象为空,那么不要尝试调用下面的方法

getLatitude和getLongitude是返回双值的方法

对于位置检查,您可以使用以下代码。你可以把它放在你的onStart()的主活动和显示警报对话框,如果返回为false。

private boolean isLocationAccurate()
    {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT)
        {
            String provider = Settings.Secure
                    .getString(getContentResolver(), Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
            if (provider != null && !provider.contains("gps"))
            {
                return false;
            }
        }
        else
        {
            try
            {
                int status = Settings.Secure
                        .getInt(this.getContentResolver(), Settings.Secure.LOCATION_MODE);
                if (status != Settings.Secure.LOCATION_MODE_HIGH_ACCURACY)
                {
                    return false;
                }
            }
            catch (Settings.SettingNotFoundException e)
            {
                Log.e(TAG, e.getMessage());
            }
        }

        return true;
    }

自2020年9月23日起,play-services-location版本17.1.0包含了FusedLocationProviderClient.getCurrentLocation()方法,这是获得当前位置的推荐和直接的方法:

返回设备上的单个当前位置固定。与返回缓存位置的getLastLocation()不同,此方法可能导致设备上的活动位置计算。如果能在合理的时间内(几十秒)确定设备位置,将返回一个新的位置,否则将返回null。

关于详细的例子,看看codingjeremy的回答和GitHub上的官方Android位置示例- Current location (Kotlin)。

因为我不喜欢其他答案中的一些代码,下面是我的简单解决方案。这个解决方案意味着在活动或服务中可用来跟踪位置。它确保它永远不会返回太陈旧的数据,除非您显式地请求陈旧的数据。它既可以在回调模式下运行,以便在我们收到更新时获得更新,也可以在轮询模式下运行,以便轮询最新的信息。

通用LocationTracker接口。允许我们有多种类型的位置跟踪器,并轻松插入适当的一个:

package com.gabesechan.android.reusable.location;

import android.location.Location;

public interface LocationTracker {
    public interface LocationUpdateListener{
        public void onUpdate(Location oldLoc, long oldTime, Location newLoc, long newTime);
    }

    public void start();
    public void start(LocationUpdateListener update);

    public void stop();

    public boolean hasLocation();

    public boolean hasPossiblyStaleLocation();

    public Location getLocation();

    public Location getPossiblyStaleLocation();

}

ProviderLocationTracker——这个类将跟踪GPS或NETWORK的位置。

package com.gabesechan.android.reusable.location;

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class ProviderLocationTracker implements LocationListener, LocationTracker {

    // The minimum distance to change Updates in meters
    private static final long MIN_UPDATE_DISTANCE = 10; 

    // The minimum time between updates in milliseconds
    private static final long MIN_UPDATE_TIME = 1000 * 60; 

    private LocationManager lm;

    public enum ProviderType{
        NETWORK,
        GPS
    };    
    private String provider;

    private Location lastLocation;
    private long lastTime;

    private boolean isRunning;

    private LocationUpdateListener listener;

    public ProviderLocationTracker(Context context, ProviderType type) {
        lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
        if(type == ProviderType.NETWORK){
            provider = LocationManager.NETWORK_PROVIDER;
        }
        else{
            provider = LocationManager.GPS_PROVIDER;
        }
    }

    public void start(){
        if(isRunning){
            //Already running, do nothing
            return;
        }

        //The provider is on, so start getting updates.  Update current location
        isRunning = true;
        lm.requestLocationUpdates(provider, MIN_UPDATE_TIME, MIN_UPDATE_DISTANCE, this);
        lastLocation = null;
        lastTime = 0;
        return;
    }

    public void start(LocationUpdateListener update) {
        start();
        listener = update;

    }


    public void stop(){
        if(isRunning){
            lm.removeUpdates(this);
            isRunning = false;
            listener = null;
        }
    }

    public boolean hasLocation(){
        if(lastLocation == null){
            return false;
        }
        if(System.currentTimeMillis() - lastTime > 5 * MIN_UPDATE_TIME){
            return false; //stale
        }
        return true;
    }

    public boolean hasPossiblyStaleLocation(){
        if(lastLocation != null){
            return true;
        }
        return lm.getLastKnownLocation(provider)!= null;
    }

    public Location getLocation(){
        if(lastLocation == null){
            return null;
        }
        if(System.currentTimeMillis() - lastTime > 5 * MIN_UPDATE_TIME){
            return null; //stale
        }
        return lastLocation;
    }

    public Location getPossiblyStaleLocation(){
        if(lastLocation != null){
            return lastLocation;
        }
        return lm.getLastKnownLocation(provider);
    }

    public void onLocationChanged(Location newLoc) {
        long now = System.currentTimeMillis();
        if(listener != null){
            listener.onUpdate(lastLocation, lastTime, newLoc, now);
        }
        lastLocation = newLoc;
        lastTime = now;
    }

    public void onProviderDisabled(String arg0) {

    }

    public void onProviderEnabled(String arg0) {

    }

    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
    }
}

这是FallbackLocationTracker,它将通过GPS和NETWORK进行跟踪,并使用任何更准确的位置。

package com.gabesechan.android.reusable.location;

import android.content.Context;
import android.location.Location;
import android.location.LocationManager;

public class FallbackLocationTracker  implements LocationTracker, LocationTracker.LocationUpdateListener {


    private boolean isRunning;

    private ProviderLocationTracker gps;
    private ProviderLocationTracker net;

    private LocationUpdateListener listener;

    Location lastLoc;
    long lastTime;

    public FallbackLocationTracker(Context context) {
        gps = new ProviderLocationTracker(context, ProviderLocationTracker.ProviderType.GPS);
        net = new ProviderLocationTracker(context, ProviderLocationTracker.ProviderType.NETWORK);
    }

    public void start(){
        if(isRunning){
            //Already running, do nothing
            return;
        }

        //Start both
        gps.start(this);
        net.start(this);
        isRunning = true;
    }

    public void start(LocationUpdateListener update) {
        start();
        listener = update;
    }


    public void stop(){
        if(isRunning){
            gps.stop();
            net.stop();
            isRunning = false;
            listener = null;
        }
    }

    public boolean hasLocation(){
        //If either has a location, use it
        return gps.hasLocation() || net.hasLocation();
    }

    public boolean hasPossiblyStaleLocation(){
        //If either has a location, use it
        return gps.hasPossiblyStaleLocation() || net.hasPossiblyStaleLocation();
    }

    public Location getLocation(){
        Location ret = gps.getLocation();
        if(ret == null){
            ret = net.getLocation();
        }
        return ret;
    }

    public Location getPossiblyStaleLocation(){
        Location ret = gps.getPossiblyStaleLocation();
        if(ret == null){
            ret = net.getPossiblyStaleLocation();
        }
        return ret;
    }

    public void onUpdate(Location oldLoc, long oldTime, Location newLoc, long newTime) {
        boolean update = false;

        //We should update only if there is no last location, the provider is the same, or the provider is more accurate, or the old location is stale
        if(lastLoc == null){
            update = true;
        }
        else if(lastLoc != null && lastLoc.getProvider().equals(newLoc.getProvider())){
            update = true;
        }
        else if(newLoc.getProvider().equals(LocationManager.GPS_PROVIDER)){
            update = true;
        }
        else if (newTime - lastTime > 5 * 60 * 1000){
            update = true;
        }

        if(update){
            if(listener != null){
                listener.onUpdate(lastLoc, lastTime, newLoc, newTime);                  
            }
            lastLoc = newLoc;
            lastTime = newTime;
        }

    }
}

由于两者都实现了LocationTracker接口,您可以很容易地改变使用哪一个的想法。要在轮询模式下运行类,只需调用start()。要在更新模式下运行它,请调用start(Listener)。

还可以看看我关于代码的博客文章

获得位置更新需要大量的代码在Android,你需要照顾

谷歌播放服务可用性检查, 更新谷歌播放服务,如果它是旧的或不可用 对话框创建GoogleApiClient和它的回调连接,断开等。 停止并释放用于位置更新的资源 处理位置权限场景 检查“位置”服务是否开启 获取最后已知位置也不是那么容易 如果在一定时间后没有得到位置,则退回到最后一个已知位置

为了简化所有这些步骤,我创建了android - easylocation(小型android库),它将照顾所有这些东西,你可以专注于业务逻辑。

所有你需要的是扩展EasyLocationActivity和这个

requestSingleLocationFix(easyLocationRequest);

or

requestLocationUpdates(easyLocationRequest);

签出示例应用程序和步骤需要在这里https://github.com/akhgupta/Android-EasyLocation