Android 获取所在城市（不接入地图SDK，使用android自带的SDK定位）

1. 使用Android 自带的SDK 定位，获取所在的经纬度

2. 通过所在经纬度得到对应的城市信息

  2.1 通过服务获取城市名（google或者baidu）

百度：http://api.map.baidu.com/geocoder?output=json&location=23.131427,113.379763&ak=esNPFDwwsXWtsQfw4NMNmur1

google：http://maps.google.com/maps/api/geocode/json?latlng=%2023.131427,113.379763&language=zh-CN&sensor=true
  

  2.2  使用Android的API 获取城市

    /**
     *使用Android 的API 获取城市
     * Address[addressLines=[0:"福建省厦门市思明区台南路"],feature=null,admin=福建省,sub-admin=莲前街道,locality=厦门市,thoroughfare=台南路,postalCode=null,
     * countryCode=CN,countryName=中国,hasLatitude=true,latitude=24.490153327372084,hasLongitude=true,longitude=118.20273875866398,phone=null,url=null,extras=null]
     */
    private fun getAddress(context: Context, location: Location?): List<Address>? {
        var result: List<Address>? = null
        try {
            if (location != null) {
                val gc = Geocoder(context, Locale.getDefault())
                result = gc.getFromLocation(location.latitude, location.longitude, 1)
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return result
    }

参考资料：https://blog.csdn.net/qq_24636637/article/details/50461284 根据经纬度获取城市名

                 百度地图官方文档：http://api.map.baidu.com/lbsapi/cloud/geocoding-api.htm （旧版，已过时）

                 对应新的文档：http://lbsyun.baidu.com/index.php?title=webapi/guide/webservice-geocoding-abroad  

                             （配额已用：0%(上限：0.6万次/天，并发峰值：1QPS   (上限：50QPS)

package com.mostone.locationmanager

import android.Manifest
import android.annotation.SuppressLint
import android.content.Context
import android.content.pm.PackageManager
import android.location.*
import android.location.LocationManager
import android.os.Build
import android.os.Bundle
import android.util.Log
import androidx.core.app.ActivityCompat
import java.util.*


/**
 * LocationManagerHelper2.kt
 * <p>
 * 类的描述: 定位辅助类
 * 创建时间: 2020/6/24 14:48
 * 修改备注: 6.0以上需要动态申请权限
 *   <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
 *   <uses-permission android:name="android.permission..ACCESS_FINE_LOCATION" />
 */

class LocationManagerHelper2 private constructor() {
    companion object {
        val instance by lazy { LocationManagerHelper2() }
    }

    private var lManager: LocationManager? = null
    private var locationProvider: String? = null

    @SuppressLint("ServiceCast")
    fun build(context: Context, listener: (MutableList<Address>?) -> Unit) {
        //获取LocationManager
        lManager = (context.getSystemService(Context.LOCATION_SERVICE)
                as LocationManager?)?.also { manager ->
            val providers = manager.getProviders(true)
            when {
                providers.contains(LocationManager.NETWORK_PROVIDER) -> { // 网络定位
                    Log.d("TAG", "如果是网络定位")
                    locationProvider = LocationManager.NETWORK_PROVIDER
                }
                providers.contains(LocationManager.GPS_PROVIDER) -> { // GPS 定位
                    Log.d("TAG", "如果是GPS定位")
                    locationProvider = LocationManager.GPS_PROVIDER
                }
                else -> {
                    Log.d("TAG", "没有可用的位置提供器")
                }
            }
            locationProvider?.let {
                if (checkSelfPermission(context)) return

                //3.获取上次的位置，一般第一次运行，此值为null
                if (manager.getLastKnownLocation(locationProvider) == null) {
                    // 监视地理位置变化，第二个和第三个参数分别为更新的最短时间minTime和最短距离minDistace
                    manager.requestLocationUpdates(
                        locationProvider, 0L, 0F,
                        getListener(context, listener)
                    )
                } else {
                    getAddress(context, manager.getLastKnownLocation(locationProvider), listener)
                }
            }
        }
    }

    private fun getListener(
        context: Context, listener: (MutableList<Address>?) -> Unit
    ): LocationListener {
        return object : LocationListener {
            override fun onLocationChanged(location: Location?) {
                location?.accuracy //精确度
                getAddress(context, location, listener)
                lManager?.removeUpdates(this)
                lManager = null
            }

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

            override fun onProviderEnabled(p0: String?) {
            }

            override fun onProviderDisabled(p0: String?) {
                lManager?.removeUpdates(this)
                lManager = null
            }
        }
    }

    private fun checkSelfPermission(context: Context): Boolean {
        // 需要检查权限,否则编译报错,想抽取成方法都不行,还是会报错。只能这样重复 code 了。
        return Build.VERSION.SDK_INT >= 23 &&
                ActivityCompat.checkSelfPermission(
                    context, Manifest.permission.ACCESS_FINE_LOCATION
                ) != PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(
                    context, Manifest.permission.ACCESS_COARSE_LOCATION
                ) != PackageManager.PERMISSION_GRANTED
    }

    /**
     * 使用Android 的API 获取城市
     * Address[addressLines=[0:"福建省厦门市思明区台南路"],feature=null,admin=福建省,sub-admin=莲前街道,locality=厦门市,thoroughfare=台南路,postalCode=null,
     * countryCode=CN,countryName=中国,hasLatitude=true,latitude=24.490153327372084,hasLongitude=true,longitude=118.20273875866398,phone=null,url=null,extras=null]
     */
    private fun getAddress(
        context: Context, location: Location?,
        listener: (MutableList<Address>?) -> Unit = {}
    ) {
        var result: MutableList<Address>? = null
        try {
            if (location != null) {
                val gc = Geocoder(context, Locale.getDefault())
                result = gc.getFromLocation(location.latitude, location.longitude, 1)
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }
        listener.invoke(result)
    }
}