5 android google-maps geolocation android-gps google-location-services
我正在尝试使用本教程实现Google地图以获取当前位置
问题是，这是没有得到我的当前位置，直到我开始我的设备的谷歌地图，并授予访问权限的谷歌位置服务。这是我的申请后，也让我的当前位置。直到设备中的位置打开时，它都可以正常工作。而当位置关闭它需要再次启动设备的谷歌地图和人的许可，谷歌位置服务。
根据指示，我已经生成的关键。
我发现在设备位置的问题mode.when我改变设备模式，以高精确度/手动节省电池，它工作正常。
因此，如何以编程方式将位置模式从默认模式（仅限设备）更改为“高精度/省电”
下面是活动的代码：
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener {
private GoogleMap mMap;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
Marker mCurrLocationMarker;
LocationRequest mLocationRequest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkLocationPermission();
}
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
//Initialize Google Play Services
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
}
else {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
@Override
public void onConnected(Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(1000);
mLocationRequest.setFastestInterval(1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
if (mCurrLocationMarker != null) {
mCurrLocationMarker.remove();
}
//Place current location marker
LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("Current Position");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
mCurrLocationMarker = mMap.addMarker(markerOptions);
//move map camera
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
//stop location updates
if (mGoogleApiClient != null) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
public boolean checkLocationPermission(){
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Asking user if explanation is needed
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted. Do the
// contacts-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
if (mGoogleApiClient == null) {
buildGoogleApiClient();
}
mMap.setMyLocationEnabled(true);
}
} else {
// Permission denied, Disable the functionality that depends on this permission.
Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
}
return;
}
// other 'case' lines to check for other permissions this app might request.
// You can add here other case statements according to your requirement.
}
}
}
这里是清单文件的代码：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.googlemap">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<permission
android:name="com.example.envent_pc03.googlemap.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-permission android:name="com.example.googlemap.permission.MAPS_RECEIVE"/>
<uses-feature android:name="android.hardware.location.gps" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true"/>
<!--
The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
Google Maps Android API v2, but you must specify either coarse or fine
location permissions for the 'MyLocation' functionality.
-->
<!--<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />-->
<!--<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />-->
<!--<uses-permission android:name="android.permission.INTERNET" />-->
<!--<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />-->
<!--
The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
Google Maps Android API v2, but you must specify either coarse or fine
location permissions for the 'MyLocation' functionality.
-->
<!--<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>-->
<!--<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />-->
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<!--
The API key for Google Maps-based APIs is defined as a string resource.
(See the file "res/values/google_maps_api.xml").
Note that the API key is linked to the encryption key used to sign the APK.
You need a different API key for each encryption key, including the release key that is used to
sign the APK for publishing.
You can define the keys for the debug and release targets in src/debug/ and src/release/.
-->
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="@string/google_maps_key" />
<activity
android:name=".MapsActivity"
android:label="@string/title_activity_maps">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
在请求位置更新之前，您需要根据需要检查正确的位置设置。
创建一个LocationSettingsRequest.Builder并添加应用程序将使用的所有LocationRequests：
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder().addLocationRequest(mLocationRequest);
使用以下命令检查是否满足位置设置
PendingResult<LocationSettingsResult> result =
LocationServices.SettingsApi.checkLocationSettings(mGoogleClient, builder.build());
当PendingResult返回时，客户端可以通过查看LocationSettingsResult对象中的状态代码来检查位置设置。
result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
@Override
public void onResult(LocationSettingsResult result) {
final Status status = result.getStatus();
final LocationSettingsStates = result.getLocationSettingsStates();
switch (status.getStatusCode()) {
case LocationSettingsStatusCodes.SUCCESS:
// All location settings are satisfied. The client can initialize location
// requests here.
...
break;
case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
// Location settings are not satisfied. But could be fixed by showing the user
// a dialog.
try {
// Show the dialog by calling startResolutionForResult(),
// and check the result in onActivityResult().
status.startResolutionForResult(
MapsActivity.this,
REQUEST_CHECK_SETTINGS);
} catch (SendIntentException e) {
// Ignore the error.
}
break;
case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
// Location settings are not satisfied. However, we have no way to fix the
// settings so we won't show the dialog.
...
break;
}
}
});
对话框的结果将通过onActivityResult（int，int，Intent）返回。
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
final LocationSettingsStates states = LocationSettingsStates.fromIntent(intent);
switch (requestCode) {
case REQUEST_CHECK_SETTINGS:
switch (resultCode) {
case Activity.RESULT_OK:
// All required changes were successfully made
...
break;
case Activity.RESULT_CANCELED:
// The user was asked to change settings, but chose not to
...
break;
default:
break;
}
break;
}
}
作为参考，请阅读SettingsApi文档，该文档很好地解释了这种情况。
或者，您可以直接将用户重定向到位置设置页面。
int locationMode = Settings.Secure.getInt(activityUnderTest.getContentResolver(), Settings.Secure.LOCATION_MODE);
检查location_mode以获取可能的返回值。
if(locationMode == LOCATION_MODE_HIGH_ACCURACY) {
//request location updates
} else { //redirect user to settings page
startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
}