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

        val locationManager=getSystemService(Context.LOCATION_SERVICE)as LocationManager

        // 位置情報のユーザー許可を確認
        if (ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION )
            != PackageManager.PERMISSION_GRANTED
        ) {
            // 許可がなければ許可を求める
            val permissions = arrayOf<String>(Manifest.permission.ACCESS_FINE_LOCATION)
            ActivityCompat.requestPermissions(this, permissions, 1000)
            // 求めた結果はonRequestPermissionsResult
            return
        }

        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0L,0F,GPSLocationListener())

    }

    // パーミッション許可を求めた結果
    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)

        if (requestCode==1000 && grantResults[0]==PackageManager.PERMISSION_GRANTED){

            //パーミッションが許可された場合
            val locationManager = getSystemService(Context.LOCATION_SERVICE) as LocationManager
            val locationListener = GPSLocationListener()

            // パーミッション許可を求めた結果を確認しているので不要に思えるが、
            // ↓ locationManager.requestLocationUpdates を呼ぶ前にかならず必要なだけ
            if (ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED){
                return
            }
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0L,0F,locationListener)

        }

    }