从Google地图获取经度和纬度的不断更新

Question

因此，我试图创建一个按钮，该按钮将向我显示当前的经度和纬度，并在移动时显示新的经度和纬度，我正在尝试使用Google Maps API进行此操作。我正在尝试通读文档，但没有看到任何可用的方法。另外，我是android编程的新手，所以我不知道文档的编写方式是否有所不同。我看到了使用Location_Manager的教程，因此让我认为我不需要使用Google。请帮助我在这里的墙上。

Answer 1

首先将此添加到您的build.gradle：

compile 'com.google.android.gms:play-services:11.0.0'

然后您可以使用此类Wherebouts.java：

import android.location.Location;
import android.os.Looper;
import android.util.Log;

import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationSettingsRequest;

/**
 * Uses Google Play API for obtaining device locations
 * Created by alejandro.tkachuk 
 * [email protected]
 * www.calculistik.com Mobile Development
 */

public class Wherebouts {

    private static final Wherebouts instance = new Wherebouts();

    private static final String TAG = Wherebouts.class.getSimpleName();

    private FusedLocationProviderClient mFusedLocationClient;
    private LocationCallback locationCallback;
    private LocationRequest locationRequest;
    private LocationSettingsRequest locationSettingsRequest;

    private Workable<GPSPoint> workable;

    private static final long UPDATE_INTERVAL_IN_MILLISECONDS = 1000;
    private static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS = 1000;

    private Wherebouts() {
        this.locationRequest = new LocationRequest();
        this.locationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
        this.locationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
        this.locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder();
        builder.addLocationRequest(this.locationRequest);
        this.locationSettingsRequest = builder.build();

        this.locationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                super.onLocationResult(locationResult); // why? this. is. retarded. Android.
                Location currentLocation = locationResult.getLastLocation();

                GPSPoint gpsPoint = new GPSPoint(currentLocation.getLatitude(), currentLocation.getLongitude());
                Log.i(TAG, "Location Callback results: " + gpsPoint);
                if (null != workable)
                    workable.work(gpsPoint);
            }
        };

        this.mFusedLocationClient = LocationServices.getFusedLocationProviderClient(MainApplication.getAppContext());
        this.mFusedLocationClient.requestLocationUpdates(this.locationRequest,
                this.locationCallback, Looper.myLooper());
    }

    public static Wherebouts instance() {
        return instance;
    }

    public void onChange(Workable<GPSPoint> workable) {
        this.workable = workable;
    }

    public LocationSettingsRequest getLocationSettingsRequest() {
        return this.locationSettingsRequest;
    }

    public void stop() {
        Log.i(TAG, "stop() Stopping location tracking");
        this.mFusedLocationClient.removeLocationUpdates(this.locationCallback);
    }

}

在您的活动中，您可以通过传递一个Workable对象来使用它。一个可行的对象不过是一个自定义的类似回调对象。

 Wherebouts.instance().onChange(workable);

通过使用像Workable这样的回调，您将在Activity中编写与UI相关的代码，而将GPS的使用工作留给了诸如Wherebouts之类的帮助器类。

    new Workable<GPSPoint>() {
        @Override
        public void work(GPSPoint gpsPoint) {
            // draw something in the UI with this new data
        }
    };