基于百度地图api的移动路径绘制以及距离计算

以下代码能够在地图上绘制自己走过的路径，有一个计时器，一个路程显示。按下“开始跑步”就可以开始绘制轨迹并同时开始计时。

以下是MainActivity文件

public class MainActivity extends Activity {
   
   
    // int count=-0;
    MapView mMapView = null;
    LocationClient mLocClient;
    public MyLocationListenner myListener = new MyLocationListenner();
    private LocationMode mCurrentMode;
    BitmapDescriptor mCurrentMarker;
    // double distance=0;

    BaiduMap mBaiduMap;
    private Timer timer = new Timer();
    private TimerTask task;
    // List<LatLng> points = new ArrayList<LatLng>();
    List<LatLng> pointstwo = new ArrayList<LatLng>();
    LatLng p1;
    LatLng p2;
    // UI相关
    OnCheckedChangeListener radioButtonListener;
    Button requestLocButton, startButton,stopButton;
    private TextView tvDistance;
    boolean isFirstLoc = true;// 是否首次定位

    private Handler handler = new Handler() {

        public void handleMessage(Message msg) {
            // 调用相机回调接口由于MainActivity已经实现了回调接口，所以MainActivity.this即可

            if (msg.what == 1) {
                // if(points.size()>3){
   
   
                // pointstwo.add((LatLng)points.get(points.size()-3));
                // pointstwo.add((LatLng)points.get(points.size()-2));
                // pointstwo.add((LatLng)points.get(points.size()-1));
                // }else{
   
   
                // pointstwo.add((LatLng)points.get(count));
                // }
                // Log.d("points",""+points.get(points.size()-3).latitude);
                // Log.d("points",""+points.get(points.size()-2).latitude);
                // Log.d("points",""+points.get(points.size()-1).latitude);
                pointstwo.add(p1);
                pointstwo.add(p2);
                // distance+=DistanceUtil. getDistance(p1, p2);
                // LatLng llDot = new LatLng(p2.latitude,p2.longitude);
                // try{
   
   
                OverlayOptions ooDot = new DotOptions().center(p2).radius(6)
                        .color(0xAAFF0000);
                mBaiduMap.addOverlay(ooDot);

                OverlayOptions ooPolyline = new PolylineOptions().width(4)
                        .color(0xAAFF0000).points(pointstwo);
                mBaiduMap.addOverlay(ooPolyline);
                p1 = p2;
                mLocClient.requestLocation();
                // }catch(Exception e){
   
   
                // e.printStackTrace();
                // }

            }
        }

    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // 使屏幕不显示标题栏(必须要在setContentView方法执行前执行)
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        // 隐藏状态栏，使内容全屏显示(必须要在setContentView方法执行前执行)
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
        // 在使用SDK各组件之前初始化context信息，传入ApplicationContext
        // 注意该方法要再setContentView方法之前实现
        SDKInitializer.initialize(getApplicationContext());
        /*
         * forbid lock screen
         */
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON,
                WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        setContentView(R.layout.activity_main);

        // 获取地图控件引用
        Log.d("points", "wwww");

        requestLocButton = (Button) findViewById(R.id.button1);
        mCurrentMode = LocationMode.NORMAL;
        requestLocButton.setText("普通");
        OnClickListener btnClickListener = new OnClickListener() {
            public void onClick(View v) {
                switch (mCurrentMode) {
                case NORMAL:
                    requestLocButton.setText("跟随");
                    mCurrentMode = LocationMode.FOLLOWING;
                    mBaiduMap
                            .setMyLocationConfigeration(new MyLocationConfiguration(
                                    mCurrentMode, true, mCurrentMarker));
                    break;
                case COMPASS:
                    requestLocButton.setText("普通");
                    mCurrentMode = LocationMode.NORMAL;
                    mBaiduMap
                            .setMyLocationConfigeration(new MyLocationConfiguration(
                                    mCurrentMode, true, mCurrentMarker));
                    break;
                case FOLLOWING:
                    requestLocButton.setText("罗盘");
                    mCurrentMode = LocationMode.COMPASS;

                    mBaiduMap
                            .setMyLocationConfigeration(new MyLocationConfiguration(
                                    mCurrentMode, true, mCurrentMarker));
                    break;
                }
            }
        };
        requestLocButton.setOnClickListener(btnClickListener);

        RadioGroup group = (RadioGroup) this.findViewById(R.id.radioGroup);
        radioButtonListener = new OnCheckedChangeListener() {