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
class MyLocation {
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled = false;
boolean network_enabled = false;
public boolean getLocation(Context context, LocationResult result) {
// I use LocationResult callback class to pass location value from
// MyLocation to user code.
locationResult = result;
if (lm == null)
lm = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
// Exceptions will be thrown if the provider is not permitted.
try {
gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
}
catch (Exception ex) {
}
try {
network_enabled = lm
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
}
catch (Exception ex) {
}
// Don't start listeners if no provider is enabled.
if (!gps_enabled && !network_enabled)
return false;
if (gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
locationListenerGps);
if (network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0,
locationListenerNetwork);
timer1 = new Timer();
timer1.schedule(new GetLastLocation(), 5000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
class GetLastLocation extends TimerTask {
@Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc = null, gps_loc = null;
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);
}
}
public static abstract class LocationResult {
public abstract void gotLocation(Location location);
}
}
我希望这对你有所帮助……
其他回答
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;
}
你需要使用latest/最新的
GoogleApiClient Api
基本上你需要做的是:
private GoogleApiClient mGoogleApiClient;
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
然后
@Override
public void onConnected(Bundle connectionHint) {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));
mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));
}
}
为最准确可靠的定位。请看我的帖子:
https://stackoverflow.com/a/33599228/2644905
不要使用LocationListener,它是不准确的,有延迟响应。老实说,这更容易实现。 请阅读文档:https://developers.google.com/android/reference/com/google/android/gms/common/api/GoogleApiClient
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
}
}
GoogleSamples有详细的例子使用最新的FusedLocationProviderApi。 不幸的是,被点赞最多的答案都过时了。
按照下面的例子使用FusedLocationProviderApi实现位置服务
https://github.com/googlesamples/android-play-location/tree/master/LocationUpdates
https://github.com/googlesamples/android-play-location/blob/master/LocationUpdates/app/src/main/java/com/google/android/gms/location/sample/locationupdates/MainActivity.java
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。
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