在Android应用程序中单击按钮显示我的位置

我在地图上创建了一个浮动按钮。我想在单击该按钮时在地图上显示当前位置。

这些将最终用户视为一个过程。但接收位置并在地图上显示它实际上是两个过程。我构建了一个类，因为我需要在我的用例中使用它。但我可以告诉你如何与你的案例相结合

class LocationTracker(
    val activity: FragmentActivity,
    val locationTrackerListener: LocationTrackerListener
) {

    private var fusedLocationClient: FusedLocationProviderClient =
        LocationServices.getFusedLocationProviderClient(activity)

    private var locationCallback: LocationCallback? = null
    private var locationRequest: LocationRequest? = null

    fun startLocationRequestProcess() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_COARSE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
            ) {
                activity.requestPermissions(
                    arrayOf(
                        Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.ACCESS_FINE_LOCATION
                    ), REQUEST_LOCATION_PERMISSION
                )
            } else {
                getUserLocation()
            }
        } else {
            getUserLocation()
        }
    }

    fun getUserLocation() {
        locationRequest = LocationRequest.create()?.apply {
            interval = 10000
            fastestInterval = 5000
            priority = LocationRequest.PRIORITY_HIGH_ACCURACY
        //please check the docs for other constants. this is the minimum used
        }

        val builder = LocationSettingsRequest.Builder()
            .addLocationRequest(locationRequest!!)

        val client: SettingsClient = LocationServices.getSettingsClient(activity)
        val task: Task<LocationSettingsResponse> = client.checkLocationSettings(builder.build())

        task.addOnSuccessListener {
            updateLocation()
        }

        task.addOnFailureListener { exception ->
            if (exception is ResolvableApiException) {
                try {
                    exception.startResolutionForResult(
                        activity,
                        REQUEST_CHECK_LOCATION_SETTINGS
                    )
                } catch (sendEx: IntentSender.SendIntentException) {
                    sendEx.printStackTrace()
                }
            }
        }
    }

    fun updateLocation() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_COARSE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
            ) {
                activity.requestPermissions(
                    arrayOf(
                        Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.ACCESS_FINE_LOCATION
                    ), REQUEST_LOCATION_PERMISSION
                )
            } else {
                requestLocationUpdates()
            }
        } else {
            requestLocationUpdates()
        }
    }

    private fun requestLocationUpdates() {
        try {
            locationCallback = object : LocationCallback() {
                override fun onLocationResult(locationResult: LocationResult?) {
                    if (locationResult == null) {
                        locationTrackerListener.onLocationError()
                    } else {
                        //you've got the response
                        locationTrackerListener.onLocationResult(locationResult)
                    }
                }
            }
            fusedLocationClient.requestLocationUpdates(locationRequest, locationCallback, null)
        } catch (securityException: SecurityException) {
            securityException.printStackTrace()
        }
    }

    fun removeLocationRequest() {
        fusedLocationClient.removeLocationUpdates(locationCallback)
    }
}

在以后的课程中，您需要lat和long:

override fun onLocationResult(locationResult: LocationResult) {
        for (location in locationResult.locations) {
            addMarkerToMapAndPerhapsZoom(location.latitude, location.longitude)
        }
    }

我正在使用的界面：

interface LocationTrackerListener {
    fun onLocationError()
    fun onLocationResult(locationResult: LocationResult)
}

---

请原谅重复代码的权限，但IDE在重构时显示错误，我真的很讨厌它。你也可以考虑得到，但是问题是当用户是第一次访问应用程序时，它给出空值。p> 首先创建

MyLocation

类，如下所示：

import java.util.Timer;
import java.util.TimerTask;

import android.annotation.SuppressLint;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class MyLocation {
    Timer timer1;
    LocationManager lm;
    LocationResult locationResult;
    boolean gps_enabled = false;
    boolean network_enabled = false;

    @SuppressLint("MissingPermission")
    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 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(), 20000);
        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 {
        @SuppressLint("MissingPermission")
        @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);
    }
}

然后在googleMap类中使用它：

floatingButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                        && context.checkSelfPermission(
                        Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    context.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
                } else {
                    MyLocation.LocationResult locationResult = new MyLocation.LocationResult() {
        @Override
        public void gotLocation(Location location) {
            if (location != null) {

        LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
         CameraUpdate update = CameraUpdateFactory.newLatLngZoom(latLng, 14);
         mGoogleMap.animateCamera(update);


            }
        }
    };
    MyLocation myLocation = new MyLocation();
    myLocation.getLocation(this, locationResult);
                }
            }
        });

并且不要忘记在您的

AndroidManifest

中添加权限

ACCESS\u FINE\u LOCATION

：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

到目前为止你都尝试了什么？我已经尝试了很多东西。首先，我想到“uiSettings.setMyLocationButtonEnabled（true）；”我会做好的。但事实并非如此。我想知道如何正确地做！考虑发布你当前拥有的代码，这使得人们更容易提供帮助，否则它看起来就像是在请求代码：）我在“上下文”和“清单”中遇到了一个错误。

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />