获取位置android Kotlin

问题描述 投票:5回答:3

我最近添加了获取位置功能。当我尝试显示经度和纬度时,它返回零。

这是我的LocationListener类:

inner class MylocationListener: LocationListener {
    constructor():super(){
        mylocation= Location("me")
        mylocation!!.longitude
        mylocation!!.latitude
    }

    override fun onLocationChanged(location: Location?) {
        mylocation=location
    }

    override fun onStatusChanged(p0: String?, p1: Int, p2: Bundle?) {}

    override fun onProviderEnabled(p0: String?) {}

    override fun onProviderDisabled(p0: String?) {}
}

这是我的GetUserLocation函数:

fun GetUserLocation(){
    var mylocation= MylocationListener()
    var locationManager=getSystemService(Context.LOCATION_SERVICE) as LocationManager
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0.1f,mylocation)
}

这是我的功能,以返回我的经度和纬度:

fun getLoction (view: View){
    prgDialog!!.show();

    GetUserLocation()

    button.setTextColor(getResources().getColor(R.color.green));
    textView.text = mylocation!!.latitude.toFloat().toString()
    Toast.makeText(this, mylocation!!.latitude.toFloat().toString(), Toast.LENGTH_LONG).show()
    Toast.makeText(this, mylocation!!.longitude.toFloat().toString(), Toast.LENGTH_LONG).show()

    prgDialog!!.hide()
} 
android location kotlin
3个回答
9
投票

GetUserLocation回归时,locationManager超出范围并且可能被破坏,阻止onLocationChanged被调用并提供更新。

此外,你已经在mylocation中定义了GetUserLocation,所以它也超出了范围并进一步杀死了任何机会或者你得到了更新。

你还没有展示外部mylocation在哪里以及如何被宣告(在GetUserLocation之外),但是如果它被宣布,它被GetUserLocation内部的阴影所掩盖。所以你没有得到太多。

这是一个如何做到这一点的例子。 (变量thetext在布局xml中定义,并使用Kotlin扩展访问。)

// in the android manifest
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
// allow these through Appliation Manager if necessary

// inside a basic activity
private var locationManager : LocationManager? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    setSupportActionBar(toolbar)

    // Create persistent LocationManager reference
    locationManager = getSystemService(LOCATION_SERVICE) as LocationManager?;

    fab.setOnClickListener { view ->
        try {
            // Request location updates
            locationManager?.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0L, 0f, locationListener);
        } catch(ex: SecurityException) {
            Log.d("myTag", "Security Exception, no location available");
        }
    }
}

//define the listener
private val locationListener: LocationListener = object : LocationListener {
    override fun onLocationChanged(location: Location) {
        thetext.setText("" + location.longitude + ":" + location.latitude);
    }
    override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
    override fun onProviderEnabled(provider: String) {}
    override fun onProviderDisabled(provider: String) {}
}

4
投票

我知道现在已经很晚了,但现在Google已经让它变得更简单了。在开发人员网站中,它表示您需要创建客户端:

private lateinit var fusedLocationClient: FusedLocationProviderClient

然后onCreate获取提供者:

override fun onCreate(savedInstanceState: Bundle?) {
    // ...
    fusedLocationClient = LocationServices.getFusedLocationProviderClient(this)
}

最后,要获取您的最后一个位置,请致电:

//Don't forget to ask for permissions for ACCESS_COARSE_LOCATION 
//and ACCESS_FINE_LOCATION
@SuppressLint("MissingPermission")
private fun obtieneLocalizacion(){
    fusedLocationClient.lastLocation
            .addOnSuccessListener { location: Location? ->
                latitude =  location?.latitude
                longitude = location?.longitude
            }
}

*使用此实现测试位置(在您的应用程序gradle文件中设置)

implementation 'com.google.android.gms:play-services-location:15.0.1'

有关详细信息,请查看此链接:

Obtain last location


3
投票

我想帮助那些试图从头开始获取位置的人。以下是参考:Kotlin Get Current Location

代码将首先检查设备中的位置是打开还是关闭,然后将获取纬度和经度,并将不断更新它。

在build.gradle(Module:app)文件中放这个

compile 'com.google.android.gms:play-services:11.8.0'

activity_main.xml代码

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_marginTop="10dp"
    android:layout_marginLeft="10dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/latitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Latitude:"
        android:textSize="18sp" />
    <TextView
        android:id="@+id/latitude_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/latitude"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@+id/latitude"
        android:textSize="16sp" />
    <TextView
        android:id="@+id/longitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Longitude:"
        android:layout_marginTop="24dp"
        android:textSize="18sp" />
    <TextView
        android:id="@+id/longitude_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/longitude"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@+id/longitude"
        android:textSize="16sp"/>

</RelativeLayout>

我激活了。

import android.Manifest
import android.annotation.SuppressLint
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.location.Location
import android.location.LocationManager
import android.provider.Settings
import android.support.v4.app.ActivityCompat
import android.support.v7.app.AlertDialog
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.TextView
import android.widget.Toast
import com.google.android.gms.common.ConnectionResult
import com.google.android.gms.common.api.GoogleApiClient
import com.google.android.gms.location.LocationRequest
import com.google.android.gms.location.LocationServices
import com.google.android.gms.maps.model.LatLng

class MainActivity : AppCompatActivity(), GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener {

    private var mLatitudeTextView: TextView? = null
    private var mLongitudeTextView: TextView? = null
    private var mGoogleApiClient: GoogleApiClient? = null
    private var mLocation: Location? = null
    private var mLocationManager: LocationManager? = null

    private var mLocationRequest: LocationRequest? = null
    private val listener: com.google.android.gms.location.LocationListener? = null
    private val UPDATE_INTERVAL = (2 * 1000).toLong()  /* 10 secs */
    private val FASTEST_INTERVAL: Long = 2000 /* 2 sec */

    private var locationManager: LocationManager? = null

    private val isLocationEnabled: Boolean
        get() {
            locationManager = getSystemService(Context.LOCATION_SERVICE) as LocationManager
            return locationManager!!.isProviderEnabled(LocationManager.GPS_PROVIDER) || locationManager!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
        }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        mLatitudeTextView = findViewById(R.id.latitude_textview) as TextView
        mLongitudeTextView = findViewById(R.id.longitude_textview) as TextView

        mGoogleApiClient = GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build()

        mLocationManager = this.getSystemService(Context.LOCATION_SERVICE) as LocationManager

        Log.d("gggg","uooo");
        checkLocation() //check whether location service is enable or not in your  phone
    }

    @SuppressLint("MissingPermission")
    override fun onConnected(p0: Bundle?) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return
        }

        startLocationUpdates()

        mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient)

        if (mLocation == null) {
            startLocationUpdates()
        }
        if (mLocation != null) {

            // mLatitudeTextView.setText(String.valueOf(mLocation.getLatitude()));
            //mLongitudeTextView.setText(String.valueOf(mLocation.getLongitude()));
        } else {
            Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show()
        }
    }

    override fun onConnectionSuspended(i: Int) {
        Log.i(TAG, "Connection Suspended")
        mGoogleApiClient!!.connect()
    }

    override fun onConnectionFailed(connectionResult: ConnectionResult) {
        Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode())
    }

    override fun onStart() {
        super.onStart()
        if (mGoogleApiClient != null) {
            mGoogleApiClient!!.connect()
        }
    }

    override fun onStop() {
        super.onStop()
        if (mGoogleApiClient!!.isConnected()) {
            mGoogleApiClient!!.disconnect()
        }
    }

    @SuppressLint("MissingPermission")
    protected fun startLocationUpdates() {
        // Create the location request
        mLocationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(UPDATE_INTERVAL)
                .setFastestInterval(FASTEST_INTERVAL)
        // Request location updates
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                mLocationRequest, this)
        Log.d("reque", "--->>>>")
    }

    override fun onLocationChanged(location: Location) {

        val msg = "Updated Location: " +
                java.lang.Double.toString(location.latitude) + "," +
                java.lang.Double.toString(location.longitude)
        mLatitudeTextView!!.text = location.latitude.toString()
        mLongitudeTextView!!.text = location.longitude.toString()
        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show()
        // You can now create a LatLng Object for use with maps
        val latLng = LatLng(location.latitude, location.longitude)
    }

    private fun checkLocation(): Boolean {
        if (!isLocationEnabled)
            showAlert()
        return isLocationEnabled
    }

    private fun showAlert() {
        val dialog = AlertDialog.Builder(this)
        dialog.setTitle("Enable Location")
                .setMessage("Your Locations Settings is set to 'Off'.\nPlease Enable Location to " + "use this app")
                .setPositiveButton("Location Settings") { paramDialogInterface, paramInt ->
                    val myIntent = Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)
                    startActivity(myIntent)
                }
                .setNegativeButton("Cancel") { paramDialogInterface, paramInt -> }
        dialog.show()
    }

    companion object {

        private val TAG = "MainActivity"
    }

}
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