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
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
其他回答
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
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)。
既然谷歌Play位置服务已经推出,我建议开发者开始使用新的融合位置提供商。你会发现它更容易使用和更准确。请观看谷歌I/O视频《超越蓝点:Android位置的新功能》,由两位创建了新的谷歌Play位置服务API的人制作。
I've been working with location APIs on a number of mobile platforms, and I think what these two guys have done is really revolutionary. It's gotten rid of a huge amount of the complexities of using the various providers. Stack Overflow is littered with questions about which provider to use, whether to use last known location, how to set other properties on the LocationManager, etc. This new API that they have built removes most of those uncertainties and makes the location services a pleasure to use.
I've written an Android app that periodically gets the location using Google Play location services and sends the location to a web server where it is stored in a database and can be viewed on Google Maps. I've written both the client software (for Android, iOS, Windows Phone and Java ME) and the server software (for ASP.NET and SQL Server or PHP and MySQL). The software is written in the native language on each platform and works properly in the background on each. Lastly, the software has the MIT License. You can find the Android client here:
https://github.com/nickfox/GpsTracker/tree/master/phoneClients/android
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
}
}
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