kotlin+gps

以下是使用Kotlin实现系统GPS位置信息变化监听的示例代码：

import android.Manifest
import android.content.pm.PackageManager
import android.location.Location
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleObserver
import androidx.lifecycle.OnLifecycleEvent
class MainActivity : AppCompatActivity() {

    private val LOCATION_PERMISSION_REQUEST_CODE = 1

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

        // 检查定位权限
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), LOCATION_PERMISSION_REQUEST_CODE)
        } else {
            startLocationUpdates()
        }
    }

    private fun startLocationUpdates() {
        // 创建LocationListener
        val locationListener = object : android.location.LocationListener {
            override fun onLocationChanged(location: Location) {
                // 处理位置变化
                // 在这里可以根据需要进行相应的操作，比如更新UI或发送位置信息到服务器等
            }

            override fun onStatusChanged(provider: String?, status: Int, extras: Bundle?) {}

            override fun onProviderEnabled(provider: String?) {}

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

        // 注册LocationListener
        val locationManager = getSystemService(LOCATION_SERVICE) as LocationManager
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0f, locationListener)

        // 添加LifecycleObserver，当Activity处于非活动状态时停止位置更新
        lifecycle.addObserver(object : LifecycleObserver {
            @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
            fun onStop() {
                locationManager.removeUpdates(locationListener)
            }
        })
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == LOCATION_PERMISSION_REQUEST_CODE && grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            startLocationUpdates()
        }
    }
}

请注意，上述代码中的`R.layout.activity_main`是一个占位符，你需要将其替换为你自己的布局文件。