无法显示定位问题

package com.example.diy_baidumap;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

import com.baidu.location.LocationClient;
import com.baidu.location.LocationClientOption;
import com.baidu.mapapi.map.BaiduMap;
import com.baidu.mapapi.map.MapView;

public class MainActivity extends AppCompatActivity {
    private MapView mMapView = null;
    private BaiduMap mBaiduMap = null;

    LocationClient mLocationClient = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mMapView = findViewById(R.id.bmapView);
        mBaiduMap = mMapView.getMap();
    }

    @Override
    protected void onResume() {
        mMapView.onResume();
        super.onResume();
    }

    @Override
    protected void onPause() {
        mMapView.onPause();
        super.onPause();
    }

    @Override
    protected void onDestroy() {
        mLocationClient.stop();
        mBaiduMap.setMyLocationEnabled(false);
        mMapView.onDestroy();
        mMapView = null;
        super.onDestroy();
    }

    private final static int ITEM_ID_BAIDUMAP_NORMAL = 101;
    private final static int ITEM_ID_BAIDUMAP_SATELLITE = 102;
    private final static int ITEM_ID_BAIDUMAP_SHOW_LOCATION = 103;

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add(Menu.NONE, ITEM_ID_BAIDUMAP_NORMAL, 1, "切换为普通地图");
        menu.add(Menu.NONE, ITEM_ID_BAIDUMAP_SATELLITE, 2, "切换为卫星地图");
        menu.add(Menu.NONE, ITEM_ID_BAIDUMAP_SHOW_LOCATION, 3, "显示定位");
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case ITEM_ID_BAIDUMAP_NORMAL:
                mBaiduMap.setMapType(ITEM_ID_BAIDUMAP_NORMAL);
                break;
            case ITEM_ID_BAIDUMAP_SATELLITE:
                mBaiduMap.setMapType(BaiduMap.MAP_TYPE_SATELLITE);
                break;
            case ITEM_ID_BAIDUMAP_SHOW_LOCATION:
                mBaiduMap.setMyLocationEnabled(true);

                mLocationClient = new LocationClient(this.getApplicationContext());

                //通过LocationClientOption设置LocationClient相关参数
                LocationClientOption option = new LocationClientOption();
                option.setOpenGps(true); // 打开gps
                option.setCoorType("bd09ll"); // 设置坐标类型
                option.setScanSpan(1000);

                //设置locationClientOption
                mLocationClient.setLocOption(option);

                //注册LocationListener监听器
                MyLocationListener myLocationListener = new MyLocationListener(this.mMapView);
                mLocationClient.registerLocationListener(myLocationListener);
                //开启地图定位图层
                mLocationClient.start();
                break;
        }
        return super.onOptionsItemSelected(item);
    }
}