通过gps在谷歌地图上跳跃的位置。 （距离不准确）

Question

我的应用应该在用户走路时实时显示距离和位置，但我的输出有错误。 距离没有立即开始，但是当它开始时它会增加很多，直到它减慢一点。 根据我见过的一个例子，红色标记和蓝点应该在一起，但它们在我的应用程序中是分开的。他们两个都说我当前的位置对吗？ 红色标记和蓝点在短时间内跳跃，我没有移动，远离我的真实位置。我认为这也会导致距离的不准确。

请参阅我的输出了解更多详情

java代码

public class MainActivity extends FragmentActivity implements LocationListener{

protected LocationManager locationManager;
private GoogleMap googleMap;
Button btnStartMove,btnPause,btnResume,btnStop;
static double n=0;
Long s1,r1;
double dis=0.0;
Thread t1;
EditText userNumberInput;
boolean bool=false;
int count=0;

double speed = 1.6;
double lat1,lon1,lat2,lon2,lat3,lon3,lat4,lon4;
double dist = 0;
TextView distanceText;
float[] result;
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES =1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 3000; //in milliseconds
boolean startDistance = false;
boolean firstTime = false;
@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
    if(isGooglePlay())
    {
        setUpMapIfNeeded();
    }
    distanceText=(TextView)findViewById(R.id.Distance);
    btnStartMove=(Button)findViewById(R.id.Start);//start moving

    //prepare distance...........
    Log.d("GPS Enabled", "GPS Enabled");  
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    String provider = locationManager.getBestProvider(criteria, true);
    Location location=locationManager.getLastKnownLocation(provider);

    btnStartMove.setOnClickListener(new OnClickListener() 
    {
        @Override
        public void onClick(View v) {
            startDistance = true;
//              lat3 = location.getLatitude();
//              lon3 = location.getLongitude();
        }
    });
    if(location!= null)
    {
        //Display current location in Toast
        String message = String.format(
                "Current Location \n Longitude: %1$s \n Latitude: %2$s",
                location.getLongitude(), location.getLatitude()
        );
        Toast.makeText(MainActivity.this, message,
                Toast.LENGTH_LONG).show();

        //Display current location in textview  
        //latitude.setText("Current Latitude: " + String.valueOf(location.getLatitude())); 
        //longitude.setText("Current Longitude: " + String.valueOf(location.getLongitude()));

        //lat3 = location.getLatitude();
        //lon3 = location.getLongitude();
    }
    else if(location == null)
    {
        Toast.makeText(MainActivity.this,
                "Location is null",    
                Toast.LENGTH_LONG).show();
    }


}

private void setUpMapIfNeeded() {

    if(googleMap == null)
    {
        Toast.makeText(MainActivity.this, "Getting map",
                Toast.LENGTH_LONG).show();
        googleMap =((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.displayMap)).getMap();

        if(googleMap != null)
        {
            setUpMap();
        }
    }

}

private void setUpMap() 
{
    //Enable MyLocation Layer of Google Map
    googleMap.setMyLocationEnabled(true);

    //Get locationManager object from System Service LOCATION_SERVICE
    //LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

    //Create a criteria object to retrieve provider
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    //Get the name of the best provider
    String provider = locationManager.getBestProvider(criteria, true);
    if(provider == null)
    {
        onProviderDisabled(provider);
    }
    //set map type
    googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    //Get current location
    Location myLocation = locationManager.getLastKnownLocation(provider);
    if(myLocation != null)
    {
        onLocationChanged(myLocation);
    }       
    locationManager.requestLocationUpdates(provider, 0, 0, this);
}

private boolean isGooglePlay() 
{
    int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);

    if (status == ConnectionResult.SUCCESS)
    {

        Toast.makeText(MainActivity.this, "Google Play Services is available",
                Toast.LENGTH_LONG).show();
        return(true);
    }
    else
    {
            GooglePlayServicesUtil.getErrorDialog(status, this, 10).show();

    }
    return (false);

 }

@Override
public void onLocationChanged(Location myLocation) {
    System.out.println("speed " + myLocation.getSpeed());
//      if(myLocation.getSpeed() > speed)
//      {
        //show location on map.................
        //Get latitude of the current location
        double latitude = myLocation.getLatitude();
        //Get longitude of the current location
        double longitude = myLocation.getLongitude();
        //Create a LatLng object for the current location
        LatLng latLng = new LatLng(latitude, longitude);
        //Show the current location in Google Map
        googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        //Zoom in the Google Map
        googleMap.animateCamera(CameraUpdateFactory.zoomTo(20));
        googleMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!"));

        //show distance............................

        if(startDistance == true)
        {

            Toast.makeText(MainActivity.this,
                      "Location has changed",    
                      Toast.LENGTH_LONG).show();
                if(myLocation != null)
                {
                    //latitude.setText("Current Latitude: " + String.valueOf(loc2.getLatitude())); 
                    //longitude.setText("Current Longitude: " + String.valueOf(loc2.getLongitude()));
                    float[] results = new float[1]; 
                    Location.distanceBetween(lat3, lon3, myLocation.getLatitude(), myLocation.getLongitude(), results);
                    System.out.println("Distance is: " + results[0]);               

                    dist += results[0];            
                    DecimalFormat df = new DecimalFormat("#.##"); // adjust this as appropriate
                if(count==1)
                {
                    distanceText.setText(df.format(dist) + "meters");
                }
                    lat3=myLocation.getLatitude();
                    lon3=myLocation.getLongitude();
                    count=1;
              }

        }
        startDistance=true;
    //}


}

@Override
public void onProviderDisabled(String provider) {
    Toast.makeText(MainActivity.this,
            "Provider disabled by the user. GPS turned off",
            Toast.LENGTH_LONG).show();
}

@Override
public void onProviderEnabled(String provider) {
    Toast.makeText(MainActivity.this,
            "Provider enabled by the user. GPS turned on",
            Toast.LENGTH_LONG).show();
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    Toast.makeText(MainActivity.this, "Provider status changed",
            Toast.LENGTH_LONG).show();
}
@Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
@Override
protected void onResume() {
    super.onResume();
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
}}

似乎无法解决我的错误。我被推荐使用location.getSpeed但它返回0.