我遇到的问题是在Android Marshmallow（API 23）中获得价值0.0作为纬度和经度，即6.0。
我已经对此进行了很多搜索，但没有找到它的解决方案。我的代码完全适用于少于23的其他API版本。
我还为selfPermission设置了代码，而且所有代码都正在运行，而不是给我0.0这么晚和很长。
请查看我关注的方式：
GPSTracker.java
public class GPSTracker extends Service implements LocationListener {
private Context mContext;
// Flag for GPS status
boolean isGPSEnabled = false;
// Flag for network status
boolean isNetworkEnabled = false;
// Flag for GPS status
boolean canGetLocation = false;
Location location; // Location
double latitude; // Latitude
double longitude; // Longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1000;
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
Activity activity;
public GPSTracker() {
}
public GPSTracker(Context context, Activity activity) {
this.mContext = context;
this.activity = activity;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
// Getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// No network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
int requestPermissionsCode = 50;
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, requestPermissionsCode);
} else {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
// If GPS enabled, get latitude/longitude using GPS Services
if (isGPSEnabled) {
if (location == null) {
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);
} else {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app.
* */
public void stopUsingGPS() {
if (locationManager != null) {
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);
} else {
locationManager.removeUpdates(GPSTracker.this);
}
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/Wi-Fi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog.
* On pressing the Settings button it will launch Settings Options.
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing the Settings button.
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// On pressing the cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
DashboardActivity.java：
在onCreate（）中我初始化了GPSTracker：
gps = new GPSTracker(mContext,DashboardActivity.this);
// Check if GPS enabled
if(gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
gps.showSettingsAlert();
}
的AndroidManifest.xml
<permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
我已经浏览了Stack Overflow中提供的许多链接，但它们都没有帮助我解决这个问题。
我很感激这里有任何帮助。
答案 0 :(得分：15)
在 CommonsWare 和 Blackkara 答案的帮助下，我能够解决我的问题。
根据他们的建议，我已经更改了我的代码，并通过调试了解我的代码的每一步。
由于我遇到的问题是我的onLocationChanged（）在Marshmallow的情况下没有被解雇，但令人惊讶的是，在旧设备小于Android M或6.0的情况下它会起火。
为了解决这个问题，我已经更改了我的代码，在这里，我发布了完整的代码，以便任何有相同问题的人都可以摆脱它。
<强> GPSTracker.java
public class GPSTracker extends Service{
private Context mContext;
// Flag for GPS status
boolean isGPSEnabled = false;
// Flag for network status
boolean isNetworkEnabled = false;
// Flag for GPS status
boolean canGetLocation = false;
Location location; // Location
double latitude; // Latitude
double longitude; // Longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1000; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
Activity activity;
public GPSTracker() {
}
public GPSTracker(Context context, Activity activity) {
this.mContext = context;
this.activity = activity;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
// Getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// No network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
int requestPermissionsCode = 50;
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
// If GPS enabled, get latitude/longitude using GPS Services
if (isGPSEnabled) {
if (location == null) {
if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 50);
} else {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, mLocationListener);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app.
* */
public void stopUsingGPS() {
}
private final LocationListener mLocationListener = new LocationListener() {
@Override
public void onLocationChanged(final Location location) {
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
};
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/Wi-Fi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog.
* On pressing the Settings button it will launch Settings Options.
* */
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing the Settings button.
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// On pressing the cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
<强> DashboardActivity.java
public class DashboardActivity extends Activity {
Context mContext;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dashboard);
mContext = this;
if (ContextCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(DashboardActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
} else {
Toast.makeText(mContext,"You need have granted permission",Toast.LENGTH_SHORT).show();
gps = new GPSTracker(mContext, DashboardActivity.this);
// Check if GPS enabled
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
gps.showSettingsAlert();
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
gps = new GPSTracker(mContext, DashboardActivity.this);
// Check if GPS enabled
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
gps.showSettingsAlert();
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(mContext, "You need to grant permission", Toast.LENGTH_SHORT).show();
}
return;
}
}
}
}
Manifest.xml：
添加的权限
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
在应用程序标记中声明服务：
<service android:name=".utilities.GPSTracker"/>
答案 1 :(得分：1)
首先，删除这些：
<permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<permission android:name="android.permission.ACCESS_FINE_LOCATION" />
这些是由平台定义的，而不是你。
此外，当用户实际授予您权限时，您不会做出反应。请求您的活动中的权限，并且在获得许可之前不要创建GPSTracker的实例。如果checkSelfPermission()表示您已获得许可，那么可能会立即。否则，将使用onRequestPermissionResult()调用活动。
位置工作本身也是错误的，因为您似乎认为您将立即获得一个位置，而在大多数情况下情况并非如此。
答案 2 :(得分：1)
你可能有以下原因？
第一个原因
位置提供商没有为您提供0.0值作为纬度和经度。你得到了第一次定义的东西。因为，您没有收到新的位置或getLastKnownLocation（）返回null。因此，纬度和经度变量保持其第一个值（0.0）
double latitude;
double longitude;
第二个原因
每当你调用getLocation（）方法时，getLastKnownLocation（）方法都会做什么，直到onLocationChanged fire！ （取决于提供者）
@Override
public void onLocationChanged(Location location) {
}
详细说明'取决于提供商'
您已请求gps和网络提供商。
requestLocationUpdates(LocationManager.NETWORK_PROVIDER ... mLocationListener);
requestLocationUpdates(LocationManager.GPS_PROVIDER ... mLocationListener);
然后为两个提供者调用了getLastKnownLocation方法
locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
假设这两个提供程序返回null 。在这种情况下，您需要等到onLocationChanged方法被触发。否则，您将从getLastKnownLocation方法获取null，具体取决于提供者
@Override
public void onLocationChanged(final Location location) {
String providerName = location.getProvider();
if(providerName.equals(LocationManager.GPS_PROVIDER)){
// onLocationChanged method is fired by gps provider.
// After this point, getLastKnownLocation(); method returns not-null
// for LocationManager.GPS_PROVIDER
}
if( providerName.equals(LocationManager.NETWORK_PROVIDER)){
// onLocationChanged method is fired by network provider.
// After this point, getLastKnownLocation(); method returns not-null
// for LocationManager.NETWORK_PROVIDER
}
}
答案 3 :(得分：0)
伙计们，我解决了这个问题，此块中给出的第一个答案很好用。 为了从经度和纬度中删除0.0，只需在手机设置中转到，打开应用程序管理器并授予应用程序权限。它将显示，就像让它等待用户使用一样，我们可以将Dialog授予权限。