Android上的LocationManager API似乎对一个只需要偶尔粗略估计用户位置的应用程序来说有点麻烦。
我正在开发的应用程序本身并不是一个定位应用程序，但它确实需要获取用户的位置，以便显示附近企业的列表。它不需要担心用户是否在移动或类似的事情。
以下是我想做的：
向用户显示附近位置的列表。预加载用户的位置，以便在“活动X”中需要它时，它将可用。我并不特别关心更新的准确性或频率。只要不太远，只要抓住一个位置就足够了。也许如果我想变得更漂亮，我会每隔几分钟左右更新一次位置，但这不是一个很大的优先事项。适用于任何具有GPS或网络位置提供商的设备。
这似乎并不难，但在我看来，我必须组建两个不同的位置提供商（GPS和NETWORK），并管理每个提供商的生命周期。不仅如此，我还必须在多个活动中复制相同的代码以满足#2。过去，我曾尝试使用getBestProvider（）将解决方案简化为仅使用一个位置提供程序，但这似乎只提供了最好的“理论”提供程序，而不是实际会为您提供最佳结果的提供程序。
有没有更简单的方法来实现这一点？
当前回答
建议使用LocationClient：
首先，定义位置更新间隔值。根据您的需要进行调整。
private static final int MILLISECONDS_PER_SECOND = 1000;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
让您的活动实现GooglePlayServicesClient.ConnectionCallbacks、GooglePlayServicesClient OnConnectionFailedListener和LocationListener。
public class LocationActivity extends Activity implements
GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {}
然后，在Activity的onCreate（）方法中设置LocationClient：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mLocationClient = new LocationClient(this, this, this);
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRequest.setInterval(UPDATE_INTERVAL);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}
将所需方法添加到“活动”中；onConnected（）是LocationClient连接时调用的方法。onLocationChanged（）是检索最新位置的位置。
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.w(TAG, "Location client connection failed");
}
@Override
public void onConnected(Bundle dataBundle) {
Log.d(TAG, "Location client connected");
mLocationClient.requestLocationUpdates(mLocationRequest, this);
}
@Override
public void onDisconnected() {
Log.d(TAG, "Location client disconnected");
}
@Override
public void onLocationChanged(Location location) {
if (location != null) {
Log.d(TAG, "Updated Location: " + Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude()));
} else {
Log.d(TAG, "Updated location NULL");
}
}
确保连接/断开LocationClient，以便它仅在绝对必要时使用额外的电池，这样GPS不会无限期运行。LocationClient必须连接才能从中获取数据。
public void onResume() {
super.onResume();
mLocationClient.connect();
}
public void onStop() {
if (mLocationClient.isConnected()) {
mLocationClient.removeLocationUpdates(this);
}
mLocationClient.disconnect();
super.onStop();
}
获取用户的位置。首先尝试使用LocationClient；如果失败，请返回LocationManager。
public Location getLocation() {
if (mLocationClient != null && mLocationClient.isConnected()) {
return mLocationClient.getLastLocation();
} else {
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
if (locationManager != null) {
Location lastKnownLocationGPS = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (lastKnownLocationGPS != null) {
return lastKnownLocationGPS;
} else {
return locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
} else {
return null;
}
}
}
其他回答
在搜索了如何获得最佳精确用户位置的最佳实现后，我成功地结合了所有最佳方法，并提出了以下类：
/**
* Retrieve accurate location from GPS or network services.
*
*
* Class usage example:
*
* public void onCreate(Bundle savedInstanceState) {
* ...
* my_location = new MyLocation();
* my_location.init(main.this, locationResult);
* }
*
*
* public LocationResult locationResult = new LocationResult(){
* @Override
* public void gotLocation(final Location location){
* // do something
* location.getLongitude();
* location.getLatitude();
* }
* };
*/
class MyLocation{
/**
* If GPS is enabled.
* Use minimal connected satellites count.
*/
private static final int min_gps_sat_count = 5;
/**
* Iteration step time.
*/
private static final int iteration_timeout_step = 500;
LocationResult locationResult;
private Location bestLocation = null;
private Handler handler = new Handler();
private LocationManager myLocationManager;
public Context context;
private boolean gps_enabled = false;
private int counts = 0;
private int sat_count = 0;
private Runnable showTime = new Runnable() {
public void run() {
boolean stop = false;
counts++;
System.println("counts=" + counts);
//if timeout (1 min) exceeded, stop tying
if(counts > 120){
stop = true;
}
//update last best location
bestLocation = getLocation(context);
//if location is not ready or don`t exists, try again
if(bestLocation == null && gps_enabled){
System.println("BestLocation not ready, continue to wait");
handler.postDelayed(this, iteration_timeout_step);
}else{
//if best location is known, calculate if we need to continue to look for better location
//if gps is enabled and min satellites count has not been connected or min check count is smaller then 4 (2 sec)
if(stop == false && !needToStop()){
System.println("Connected " + sat_count + " sattelites. continue waiting..");
handler.postDelayed(this, iteration_timeout_step);
}else{
System.println("#########################################");
System.println("BestLocation found return result to main. sat_count=" + sat_count);
System.println("#########################################");
// removing all updates and listeners
myLocationManager.removeUpdates(gpsLocationListener);
myLocationManager.removeUpdates(networkLocationListener);
myLocationManager.removeGpsStatusListener(gpsStatusListener);
sat_count = 0;
// send best location to locationResult
locationResult.gotLocation(bestLocation);
}
}
}
};
/**
* Determine if continue to try to find best location
*/
private Boolean needToStop(){
if(!gps_enabled){
return true;
}
else if(counts <= 4){
return false;
}
if(sat_count < min_gps_sat_count){
//if 20-25 sec and 3 satellites found then stop
if(counts >= 40 && sat_count >= 3){
return true;
}
return false;
}
}
return true;
}
/**
* Best location abstract result class
*/
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
/**
* Initialize starting values and starting best location listeners
*
* @param Context ctx
* @param LocationResult result
*/
public void init(Context ctx, LocationResult result){
context = ctx;
locationResult = result;
myLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
gps_enabled = (Boolean) myLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
bestLocation = null;
counts = 0;
// turning on location updates
myLocationManager.requestLocationUpdates("network", 0, 0, networkLocationListener);
myLocationManager.requestLocationUpdates("gps", 0, 0, gpsLocationListener);
myLocationManager.addGpsStatusListener(gpsStatusListener);
// starting best location finder loop
handler.postDelayed(showTime, iteration_timeout_step);
}
/**
* GpsStatus listener. OnChainged counts connected satellites count.
*/
public final GpsStatus.Listener gpsStatusListener = new GpsStatus.Listener() {
public void onGpsStatusChanged(int event) {
if(event == GpsStatus.GPS_EVENT_SATELLITE_STATUS){
try {
// Check number of satellites in list to determine fix state
GpsStatus status = myLocationManager.getGpsStatus(null);
Iterable<GpsSatellite>satellites = status.getSatellites();
sat_count = 0;
Iterator<GpsSatellite>satI = satellites.iterator();
while(satI.hasNext()) {
GpsSatellite satellite = satI.next();
System.println("Satellite: snr=" + satellite.getSnr() + ", elevation=" + satellite.getElevation());
sat_count++;
}
} catch (Exception e) {
e.printStackTrace();
sat_count = min_gps_sat_count + 1;
}
System.println("#### sat_count = " + sat_count);
}
}
};
/**
* Gps location listener.
*/
public final LocationListener gpsLocationListener = new LocationListener(){
@Override
public void onLocationChanged(Location location){
}
public void onProviderDisabled(String provider){}
public void onProviderEnabled(String provider){}
public void onStatusChanged(String provider, int status, Bundle extras){}
};
/**
* Network location listener.
*/
public final LocationListener networkLocationListener = new LocationListener(){
@Override
public void onLocationChanged(Location location){
}
public void onProviderDisabled(String provider){}
public void onProviderEnabled(String provider){}
public void onStatusChanged(String provider, int status, Bundle extras){}
};
/**
* Returns best location using LocationManager.getBestProvider()
*
* @param context
* @return Location|null
*/
public static Location getLocation(Context context){
System.println("getLocation()");
// fetch last known location and update it
try {
LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
String strLocationProvider = lm.getBestProvider(criteria, true);
System.println("strLocationProvider=" + strLocationProvider);
Location location = lm.getLastKnownLocation(strLocationProvider);
if(location != null){
return location;
}
return null;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
如果启用gps，此类将尝试连接到min_gps_sat_count卫星。Else返回LocationManager.getBestProvider（）位置。检查代码！
在android系统中获取位置更新需要很多东西，需要大量的bolierplate代码。
你需要照顾好
Google Play服务可用性检查，更新Google play服务，如果它是旧的或不可用GoogleApiClient的对话框创建及其连接、断开等回调。停止并释放用于位置更新的资源处理位置权限方案检查位置服务是否打开或关闭获取最新位置也不是那么容易如果在一定时间后未找到位置，则回退到最后一个已知位置
我已经创建了Android EasyLocation（小型Android库），它将处理所有这些事情，您可以专注于业务逻辑。
您只需要扩展EasyLocationActivity
requestSingleLocationFix(easyLocationRequest);
or
requestLocationUpdates(easyLocationRequest);
点击此处查看示例应用程序和所需步骤https://github.com/akhgupta/Android-EasyLocation
我已经在demonuts.com上写了详细的教程，介绍了当前位置。您可以在这里找到更多描述，也可以下载整个演示源代码以更好地理解。
这里已经有很多答案，但我想展示使用Google API获取位置的最新方法，这样新程序员就可以使用新方法：
首先，将其放在gradle文件中
compile 'com.google.android.gms:play-services:8.4.0'
然后实现必要的接口
public class MainActivity extends BaseActivitiy implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener
声明实例
private GoogleApiClient mGoogleApiClient;
private Location mLocation;
private LocationManager locationManager;
private LocationRequest mLocationRequest;
将其放入onCreate（）中
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
最后，重写必要的方法
@Override
public void onConnected(Bundle bundle) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if(mLocation == null){
startLocationUpdates();
}
if (mLocation != null) {
double latitude = mLocation.getLatitude();
double longitude = mLocation.getLongitude();
} else {
// Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
}
}
protected void startLocationUpdates() {
// Create the location request
mLocationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(UPDATE_INTERVAL)
.setFastestInterval(FASTEST_INTERVAL);
// Request location updates
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
mLocationRequest, this);
Log.d("reque", "--->>>>");
}
@Override
public void onConnectionSuspended(int i) {
Log.i(TAG, "Connection Suspended");
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
}
@Override
public void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
public void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
@Override
public void onLocationChanged(Location location) {
}
在运行应用程序之前，不要忘记在设备中启动GPS。
Kotlin版本的@Fedor Greate回答：
类的用法：
val locationResult = object : MyLocation.LocationResult() {
override fun gotLocation(location: Location?) {
val lat = location!!.latitude
val lon = location.longitude
Toast.makeText(context, "$lat --SLocRes-- $lon", Toast.LENGTH_SHORT).show()
}
}
val myLocation = MyLocation()
myLocation.getLocation(inflater.context, locationResult)
MyLocation类：
class MyLocation {
internal lateinit var timer1: Timer
internal var lm: LocationManager? = null
internal lateinit var locationResult: LocationResult
internal var gps_enabled = false
internal var network_enabled = false
internal var locationListenerGps: LocationListener = object : LocationListener {
override fun onLocationChanged(location: Location) {
timer1.cancel()
locationResult.gotLocation(location)
lm!!.removeUpdates(this)
lm!!.removeUpdates(locationListenerNetwork)
}
override fun onProviderDisabled(provider: String) {}
override fun onProviderEnabled(provider: String) {}
override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
}
internal var locationListenerNetwork: LocationListener = object : LocationListener {
override fun onLocationChanged(location: Location) {
timer1.cancel()
locationResult.gotLocation(location)
lm!!.removeUpdates(this)
lm!!.removeUpdates(locationListenerGps)
}
override fun onProviderDisabled(provider: String) {}
override fun onProviderEnabled(provider: String) {}
override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
}
fun getLocation(context: Context, result: LocationResult): Boolean {
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult = result
if (lm == null)
lm = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager?
//exceptions will be thrown if provider is not permitted.
try {
gps_enabled = lm!!.isProviderEnabled(LocationManager.GPS_PROVIDER)
} catch (ex: Exception) {
}
try {
network_enabled = lm!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
} catch (ex: Exception) {
}
//don't start listeners if no provider is enabled
if (!gps_enabled && !network_enabled)
return false
if (ActivityCompat.checkSelfPermission(context,
Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) run {
ActivityCompat.requestPermissions(context as Activity,
arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION), 111)
}
if (gps_enabled)
lm!!.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0f, locationListenerGps)
if (network_enabled)
lm!!.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0f, locationListenerNetwork)
timer1 = Timer()
timer1.schedule(GetLastLocation(context), 20000)
return true
}
internal inner class GetLastLocation(var context: Context) : TimerTask() {
override fun run() {
lm!!.removeUpdates(locationListenerGps)
lm!!.removeUpdates(locationListenerNetwork)
var net_loc: Location? = null
var gps_loc: Location? = null
if (ActivityCompat.checkSelfPermission(context,
Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
) run {
ActivityCompat.requestPermissions(context as Activity,
arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION),111)
}
if (gps_enabled)
gps_loc = lm!!.getLastKnownLocation(LocationManager.GPS_PROVIDER)
if (network_enabled)
net_loc = lm!!.getLastKnownLocation(LocationManager.NETWORK_PROVIDER)
//if there are both values use the latest one
if (gps_loc != null && net_loc != null) {
if (gps_loc.getTime() > net_loc.getTime())
locationResult.gotLocation(gps_loc)
else
locationResult.gotLocation(net_loc)
return
}
if (gps_loc != null) {
locationResult.gotLocation(gps_loc)
return
}
if (net_loc != null) {
locationResult.gotLocation(net_loc)
return
}
locationResult.gotLocation(null)
}
}
abstract class LocationResult {
abstract fun gotLocation(location: Location?)
}
}
通过使用FusedLocationProviderApi，这是最新的API，也是在Android中获取位置的最佳可能性。将其添加到build.gradle文件中
dependencies {
compile 'com.google.android.gms:play-services:6.5.87'
}
您可以通过此url获取完整的源代码http://javapapers.com/android/android-location-fused-provider/
