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

我已经发布了一个小的库,可以很容易地在Android中获取位置数据,它甚至照顾到Android M运行时权限。

您可以在这里查看它:https://github.com/julioromano/RxLocation并使用它或其源代码作为实现的示例。

其他回答

Edit 2022:不要使用这个库,因为该库有内存泄漏,不再支持/更新。

我将推荐使用智能位置库 使用起来非常简单,它很好地包装了位置逻辑。

启动位置服务:

SmartLocation.with(context).location()
    .start(new OnLocationUpdatedListener() { ... });

如果你只想获得一个单一的位置(不是周期性的),你可以使用oneFix修饰符。例子:

SmartLocation.with(context).location()
    .oneFix()
    .start(new OnLocationUpdatedListener() { ... });

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)。

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;
    }

到2020年下半年,有一种更简单的方法来做到这一点。

不包括请求权限(我将在底部包含更新的开发人员),下面是代码。

记住,你至少需要在你的依赖项中包含这个版本的库(在应用程序的build.gradle中):

implementation 'com.google.android.gms:play-services-location:17.1.0'

... 当然还有你清单上的准许

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Kotlin(首先是设置):

private val fusedLocationClient: FusedLocationProviderClient by lazy {
    LocationServices.getFusedLocationProviderClient(applicationContext)
}

private var cancellationTokenSource = CancellationTokenSource()

然后是主代码(FINE_LOCATION):

private fun requestCurrentLocation() {
    // Check Fine permission
    if (ActivityCompat.checkSelfPermission(
            this,
            Manifest.permission.ACCESS_FINE_LOCATION) ==
        PackageManager.PERMISSION_GRANTED) {

        // Main code
        val currentLocationTask: Task<Location> = fusedLocationClient.getCurrentLocation(
            PRIORITY_HIGH_ACCURACY,
            cancellationTokenSource.token
        )

        currentLocationTask.addOnCompleteListener { task: Task<Location> ->
            val result = if (task.isSuccessful) {
                val result: Location = task.result
                "Location (success): ${result.latitude}, ${result.longitude}"
            } else {
                val exception = task.exception
                "Location (failure): $exception"
            }

            Log.d(TAG, "getCurrentLocation() result: $result")
        }
    } else {
        // Request fine location permission (full code below).
}

如果你更喜欢Java,它看起来像这样:

public class JavaVersion extends AppCompatActivity {

    private final String TAG = "MainActivity";

    // The Fused Location Provider provides access to location APIs.
    private FusedLocationProviderClient fusedLocationClient;

    // Allows class to cancel the location request if it exits the activity.
    // Typically, you use one cancellation source per lifecycle.
    private final CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
    }
    ...
    
    private void requestCurrentLocation() {
        Log.d(TAG, "requestCurrentLocation()");
        // Request permission
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.ACCESS_FINE_LOCATION) ==
                PackageManager.PERMISSION_GRANTED) {
            
            // Main code
            Task<Location> currentLocationTask = fusedLocationClient.getCurrentLocation(
                    PRIORITY_HIGH_ACCURACY,
                    cancellationTokenSource.getToken()
            );

            currentLocationTask.addOnCompleteListener((new OnCompleteListener<Location>() {
                @Override
                public void onComplete(@NonNull Task<Location> task) {

                    String result = "";

                    if (task.isSuccessful()) {
                        // Task completed successfully
                        Location location = task.getResult();
                        result = "Location (success): " +
                                location.getLatitude() +
                                ", " +
                                location.getLongitude();
                    } else {
                        // Task failed with an exception
                        Exception exception = task.getException();
                        result = "Exception thrown: " + exception;
                    }

                    Log.d(TAG, "getCurrentLocation() result: " + result);
                }
            }));
        } else {
            // TODO: Request fine location permission
            Log.d(TAG, "Request fine location permission.");
        }
    }
    ...
}

的参数:

PRIORITY类型是自解释的。(其他选项是PRIORITY_BALANCED_POWER_ACCURACY, PRIORITY_LOW_POWER和PRIORITY_NO_POWER。) CancellationToken——如果用户导航离开Activity,这个token允许你取消请求。

操作(Kotlin):

override fun onStop() {
    super.onStop()
    // Cancels location request (if in flight).
    cancellationTokenSource.cancel()
}

就是这样。

现在,这使用FusedLocationProviderClient,这是一个谷歌播放服务api。

这意味着这适用于所有带有谷歌Play Store的Android设备(数量很多)。然而,对于在中国没有Play Store的设备来说,这是行不通的,所以要考虑到这一点。

对于这方面的开发人员来说,如果用户还没有批准,则需要请求精细(或粗略)位置权限,因此在上面的代码中,我将请求位置权限。

下面是完整的代码(在Kotlin中)。

我希望这对你有所帮助(让你的生活更轻松一点)!

/**
 * Demonstrates how to easily get the current location via the [FusedLocationProviderClient.getCurrentLocation].
 * The main code is in this class's requestCurrentLocation() method.
 */
class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding

    // The Fused Location Provider provides access to location APIs.
    private val fusedLocationClient: FusedLocationProviderClient by lazy {
        LocationServices.getFusedLocationProviderClient(applicationContext)
    }

    // Allows class to cancel the location request if it exits the activity.
    // Typically, you use one cancellation source per lifecycle.
    private var cancellationTokenSource = CancellationTokenSource()

    // If the user denied a previous permission request, but didn't check "Don't ask again", this
    // Snackbar provides an explanation for why user should approve, i.e., the additional rationale.
    private val fineLocationRationalSnackbar by lazy {
        Snackbar.make(
            binding.container,
            R.string.fine_location_permission_rationale,
            Snackbar.LENGTH_LONG
        ).setAction(R.string.ok) {
            requestPermissions(
                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
                REQUEST_FINE_LOCATION_PERMISSIONS_REQUEST_CODE
            )
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        val view = binding.root

        setContentView(view)
    }

    override fun onStop() {
        super.onStop()
        // Cancels location request (if in flight).
        cancellationTokenSource.cancel()
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        Log.d(TAG, "onRequestPermissionResult()")

        if (requestCode == REQUEST_FINE_LOCATION_PERMISSIONS_REQUEST_CODE) {
            when {
                grantResults.isEmpty() ->
                    // If user interaction was interrupted, the permission request
                    // is cancelled and you receive an empty array.
                    Log.d(TAG, "User interaction was cancelled.")

                grantResults[0] == PackageManager.PERMISSION_GRANTED ->
                    Snackbar.make(
                        binding.container,
                        R.string.permission_approved_explanation,
                        Snackbar.LENGTH_LONG
                    )
                        .show()

                else -> {
                    Snackbar.make(
                        binding.container,
                        R.string.fine_permission_denied_explanation,
                        Snackbar.LENGTH_LONG
                    )
                        .setAction(R.string.settings) {
                            // Build intent that displays the App settings screen.
                            val intent = Intent()
                            intent.action = Settings.ACTION_APPLICATION_DETAILS_SETTINGS
                            val uri = Uri.fromParts(
                                "package",
                                BuildConfig.APPLICATION_ID,
                                null
                            )
                            intent.data = uri
                            intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
                            startActivity(intent)
                        }
                        .show()
                }
            }
        }
    }

    fun locationRequestOnClick(view: View) {
        Log.d(TAG, "locationRequestOnClick()")

        requestCurrentLocation()
    }

    /**
     * Gets current location.
     * Note: The code checks for permission before calling this method, that is, it's never called
     * from a method with a missing permission. Also, I include a second check with my extension
     * function in case devs just copy/paste this code.
     */
    private fun requestCurrentLocation() {
        Log.d(TAG, "requestCurrentLocation()")
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.ACCESS_FINE_LOCATION) ==
            PackageManager.PERMISSION_GRANTED) {

            // Returns a single current location fix on the device. Unlike getLastLocation() that
            // returns a cached location, this method could cause active location computation on the
            // device. A single fresh location will be returned if the device location can be
            // determined within reasonable time (tens of seconds), otherwise null will be returned.
            //
            // Both arguments are required.
            // PRIORITY type is self-explanatory. (Other options are PRIORITY_BALANCED_POWER_ACCURACY,
            // PRIORITY_LOW_POWER, and PRIORITY_NO_POWER.)
            // The second parameter, [CancellationToken] allows the activity to cancel the request
            // before completion.
            val currentLocationTask: Task<Location> = fusedLocationClient.getCurrentLocation(
                PRIORITY_HIGH_ACCURACY,
                cancellationTokenSource.token
            )

            currentLocationTask.addOnCompleteListener { task: Task<Location> ->
                val result = if (task.isSuccessful) {
                    val result: Location = task.result
                    "Location (success): ${result.latitude}, ${result.longitude}"
                } else {
                    val exception = task.exception
                    "Location (failure): $exception"
                }

                Log.d(TAG, "getCurrentLocation() result: $result")
                logOutputToScreen(result)
            }
        } else {
            val provideRationale = shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_FINE_LOCATION)

            if (provideRationale) {
                fineLocationRationalSnackbar.show()
            } else {
                requestPermissions(arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), REQUEST_FINE_LOCATION_PERMISSIONS_REQUEST_CODE)
            }
        }
    }

    private fun logOutputToScreen(outputString: String) {
        val finalOutput = binding.outputTextView.text.toString() + "\n" + outputString
        binding.outputTextView.text = finalOutput
    }

    companion object {
        private const val TAG = "MainActivity"
        private const val REQUEST_FINE_LOCATION_PERMISSIONS_REQUEST_CODE = 34
    }
}

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