在Kotlin中获取新用户位置不起作用

问题描述

大家好，

我已经从类似于以下内容的教程中构建了代码。但是，使用新的Kotlin更新，它将不允许您运行 fusedLocationProviderClient.requestLocationUpdates（ parameters ），而无需进行权限检查，我不确定该如何实施。不过应该很简单。

我的问题是，在下面的 getNewLocation（）函数中，处理器未运行到 fusedLocationProviderClient !!。requestLocationUpdates （参数）以及与其关联的回调（没有错误显示，或者没有打印声明也没有指示）。这是一个主要问题，因为这意味着如果初始请求返回NULL，我将无法访问用户位置。

我真的希望在那里遇到同样的问题，以便我能帮助您解决这个令人沮丧的漏洞。

代码如下：

class MainActivity : AppCompatActivity() {

    lateinit var fusedLocationProviderClient: FusedLocationProviderClient
    lateinit var locationRequest: LocationRequest

    //Permission id
    private var PERMISSION_ID = 1000

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

        //Initiate Fused Location Provider Client
        fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this)
        btnLocation.setonClickListener {
            getLastLocation()
        }
    }

    //Function to get last location
    @SuppressLint("MissingPermission","SetTextI18n")
    private fun getLastLocation() {
        if(CheckPermission()) {
            if(isLocationEnabled()) {
                fusedLocationProviderClient.lastLocation.addOnCompleteListener {task ->
                    var location = task.result
                    if(location == null) {
                        getNewLocation()
                    } else {
                        tv_location.text = "Your current coordinates are :\nLat: " + location.latitude + " ; Long: " + location.longitude +
                                "\nYour City: " + getCityName(location.latitude,location.latitude) + ",Your Country: " + getCountryName(location.latitude,location.longitude)
                    }
                }
            } else {
                Toast.makeText(this,"Please enable your location service",Toast.LENGTH_LONG).show()
            }
        } else {
            RequestPermission()
        }
    }

    @SuppressLint("MissingPermission")
    private fun getNewLocation() {
        locationRequest = LocationRequest()
        locationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY
        locationRequest.interval = 0
        locationRequest.fastestInterval = 0
        locationRequest.numUpdates = 2
        fusedLocationProviderClient!!.requestLocationUpdates(
            locationRequest,locationCallback,Looper.myLooper()
        )
    }

    private val locationCallback = object : LocationCallback() {
        @SuppressLint("SetTextI18n")
        override fun onLocationResult(p0: LocationResult?) {
            var lastLocation = p0?.lastLocation
            if (lastLocation != null) {
                tv_location.text = "Your current coordinates are :\nLat: " + lastLocation.latitude + " ; Long: " + lastLocation.longitude +
                        "\nYour City: " + getCityName(lastLocation.latitude,lastLocation.longitude) + ",Your Country: " + getCountryName(lastLocation.latitude,lastLocation.longitude)
            }
        }
    }


    //Check user permission
    private fun CheckPermission():Boolean  {
        if(
            ActivityCompat.checkSelfPermission(this,android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED ||
                    ActivityCompat.checkSelfPermission(this,android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED

                ) {
            return true
        }

        return false
    }
    //Get user permission
    private fun RequestPermission() {
        ActivityCompat.requestPermissions(
            this,arrayOf(android.Manifest.permission.ACCESS_FINE_LOCATION,android.Manifest.permission.ACCESS_COARSE_LOCATION),PERMISSION_ID
        )
    }
    //Check location service
    private fun isLocationEnabled():Boolean {
        var locationManager :LocationManager = getSystemService(Context.LOCATION_SERVICE) as LocationManager
        return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) || locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
    }

    private fun getCityName(lat:Double,lon:Double):String {
        var CityName = ""
        var geoCoder = Geocoder(this,Locale.getDefault())
        var Adress = geoCoder.getFromLocation(lat,lon,1)
        CityName = Adress.get(0).locality
        return CityName
    }

    private fun getCountryName(lat:Double,lon:Double):String {
        var CountryName = ""
        var geoCoder = Geocoder(this,1)
        CountryName = Adress.get(0).countryName
        return CountryName
    }

    //Built in function to check permission result
    //Used it just for debugging
    override fun onRequestPermissionsResult(
        requestCode: Int,permissions: Array<out String>,grantResults: IntArray
    ) {
        if (requestCode == PERMISSION_ID) {
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                Log.d("Debug:","You have the permission")
            }
        }
    }
}

解决方法

您需要在Androidmenifest.xml文件中添加这两个权限

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