dps定位requestLocationUpdates第四个参数些什么？

Question

我是新手 自学 改代码按照视频里写的 视频里代码没问题 到我这就有问题：locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,2000,100,this); 这里的this 有问题 换成什么参数都有问题 写成this 的话 整行代码都有红线！
请大神帮忙！

 package fragment;
import android.content.Context;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.provider.Settings;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.example.luao2.jiemianzhuantiao.R;
import com.lidroid.xutils.ViewUtils;

import org.xutils.view.annotation.ViewInject;

import java.io.IOException;
import java.util.List;

import luao2.utils.SharedUtils;


/**
 * Created by Administrator on 2017/4/4.
 */

public class FragmentHome extends Fragment implements LocationListener{
    @ViewInject(R.id.index_top_city)
    private TextView topCity;
    private String cityName; //当前城市名称
    private LocationManager locationManager;


    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.home_index, null);
        ViewUtils.inject(this,view);
        //获取数据并显示

        return view;
    }

    @Override
    public void onStart() {
        super.onStart();
        //检查当前的GPS模块
        checkGPSIsOpen();
    }
    private void checkGPSIsOpen(){
        //获取当前的LocationManager对象
        locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
        boolean isOpen = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        if (!isOpen){
            //进入GPS的设置页面
            Intent intent = new Intent();
            intent.setAction(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivityForResult(intent,0);
        }
        //开始定位
        startLocation();
    }
//使用GPS定位的方法
    private void startLocation(){


        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,2000,100,this);
    }
    //接收并且处理消息
    private Handler handler = new Handler(new Handler.Callback() {
        @Override
        public boolean handleMessage(Message msg) {
            if (msg.what == 1){
                topCity.setText(cityName);
            }
            return false;
        }
    });
    //获取对应位置的经纬度并且定位城市
    private void updateWithNewLocation(Location location){
        double lat = 0.0,lng = 0.0;
        if (location !=null){
            lat = location.getLatitude();
            lng = location.getLongitude();
            Log.i("TAG","经度是"+lat+"纬度是:"+lng);
        }else {
            cityName = "无法获取城市信息";
        }
        //通过经纬度获取地址，由于地址会有多个，这个和经纬度精确度有关，本实例中定义了最大的返回数2，即在集合对象中有两个值
        List<Address> list = null;
        Geocoder ge = new Geocoder(getActivity());
        try {
            list = ge.getFromLocation(lat,lng,2);
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (list !=null && list.size()>0){
            for (int i = 0; i < list.size(); i++){
                Address ad = list.get(i);
                cityName = ad.getLocality();//获取城市
            }
        }
        //发送一条空消息
        handler.sendEmptyMessage(1);
    }

    //位置信息更改执行方法
    @Override
    public void onLocationChanged(Location location) {
        //更新当前的位置信息
        updateWithNewLocation(location);
    }
    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        //保存城市

        //停止定位
        stopLocation();
    }
    //停止定位
    private void stopLocation(){
        locationManager.removeUpdates(this);
    }
}

Answer 1

http://bbs.csdn.net/topics/390396569