Question

我在android中使用geo-location制作一个Android应用程序。我正在使用位置管理器来获取地理位置坐标。

   locationManager.requestLocationUpdates(provider, 0, 0, this);
   Location location = locationManager.getLastKnownLocation(provider);

并使用 postDelayed（）函数连续调用地理位置的 getLastKnownLocation（）。并设置间隔时间1000（1秒）。但是我在20秒后得到了答复。任何机构都能解释我为什么会这样。我是android的新手。

Answer 1

请注意，如果您设置了位置侦听器（您看起来像这样），则不应每秒都调用getLastKnownLocation()。只需使用onLocationChanged()回调中提供的最新值。

这段代码适用于我，它注册了一个位置监听器，它更新了lat / lon成员变量，然后Runnable以一秒的初始间隔运行，然后每五秒钟运行一次（5000毫秒）并显示最新的位置值。

我添加Toast以确保Runnable每5秒运行一次handler.postDelayed()。

以下是完整的活动代码：

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity implements LocationListener {

    LocationManager locationManager;
    Handler handler;
    Location location;

    double latitude;
    double longitude;

    TextView lat;
    TextView lon;

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

        handler = new Handler();

        lat = (TextView) findViewById(R.id.latitudeTextView);
        lon = (TextView) findViewById(R.id.longitudeTextView);

        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
        location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        if (location != null){
            latitude = location.getLatitude();
            longitude = location.getLongitude();
        }

        handler.postDelayed(runLocation, 1000);
    }

    public Runnable runLocation = new Runnable(){
        @Override
        public void run() {
            lat.setText(String.valueOf(latitude));
            lon.setText(String.valueOf(longitude));
            Toast.makeText(MainActivity.this, "location check", Toast.LENGTH_SHORT).show();

            MainActivity.this.handler.postDelayed(MainActivity.this.runLocation, 5000);
        }
    };


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onLocationChanged(Location location) {
        latitude = location.getLatitude();
        longitude = location.getLongitude();
    }

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

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onProviderDisabled(String provider) {

    }
}

编辑：

作为替代方案，您可以使用postDelayed()，并使用onLocationChanged()个事件。

在下面的示例中，我同时使用了NETWORK_PROVIDER和GPS_PROVIDER。

AndroidManifest.xml中需要这样做：

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

以下是修改后的代码，它将活动注册为网络位置回调和GPS位置回调的位置侦听器，最小时间间隔为1秒。请注意，事件的间隔时间间隔可能超过一秒，但启用了GPS定位后，我看到它们每秒都会进入（仅启用网络位置需要更长的时间）。

public class MainActivity extends ActionBarActivity implements LocationListener {

    LocationManager locationManager;
    Handler handler;
    Location location;

    double latitude;
    double longitude;

    TextView lat;
    TextView lon;

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

        handler = new Handler();

        lat = (TextView) findViewById(R.id.latitudeTextView);
        lon = (TextView) findViewById(R.id.longitudeTextView);

        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000, 0, this);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, this);
        location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        if (location != null){
            latitude = location.getLatitude();
            longitude = location.getLongitude();
        }

        //handler.postDelayed(runLocation, 1000);
    }
/*
    public Runnable runLocation = new Runnable(){
        @Override
        public void run() {
            lat.setText(String.valueOf(latitude));
            lon.setText(String.valueOf(longitude));
            Toast.makeText(MainActivity.this, "location check", Toast.LENGTH_SHORT).show();

            MainActivity.this.handler.postDelayed(MainActivity.this.runLocation, 5000);
        }
    };
*/

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onLocationChanged(Location location) {
        latitude = location.getLatitude();
        longitude = location.getLongitude();

        lat.setText(String.valueOf(latitude));
        lon.setText(String.valueOf(longitude));
        Toast.makeText(MainActivity.this, "location changed: " + latitude + " " + longitude, Toast.LENGTH_SHORT).show();
    }

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

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onProviderDisabled(String provider) {

    }
}

Answer 2

将此类用作普通类。

package com.ibl.commonClass;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {

private final Context mContext;

// flag for GPS status
boolean isGPSEnabled = false;

// flag for network status
boolean isNetworkEnabled = false;

// flag for GPS status
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) {
    this.mContext = context;
    getLocation();
}

public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            // First get location from Network Provider
            if (isNetworkEnabled) {
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}

/**
 * Stop using GPS listener Calling this function will stop using GPS in your
 * app
 * */
public void stopUsingGPS() {
    if (locationManager != null) {
        locationManager.removeUpdates(GPSTracker.this);
    }
}

/**
 * Function to get latitude
 * */
public double getLatitude() {
    if (location != null) {
        latitude = location.getLatitude();
    }

    // return latitude
    return latitude;
}

/**
 * Function to get longitude
 * */
public double getLongitude() {
    if (location != null) {
        longitude = location.getLongitude();
    }

    // return longitude
    return longitude;
}

/**
 * Function to check GPS/wifi enabled
 * 
 * @return boolean
 * */
public boolean canGetLocation() {
    return this.canGetLocation;
}

/**
 * Function to show settings alert dialog On pressing Settings button will
 * lauch Settings Options
 * */
public void showSettingsAlert() {
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    // Setting Dialog Title
    alertDialog.setTitle("GPS is settings");

    // Setting Dialog Message
    alertDialog
            .setMessage("GPS is not enabled. Do you want to go to settings menu?");

    // On pressing Settings button
    alertDialog.setPositiveButton("Settings",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Intent intent = new Intent(
                            Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    mContext.startActivity(intent);
                }
            });

    // on pressing cancel button
    alertDialog.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });

    // Showing Alert Message
    alertDialog.show();
}

@Override
public void onLocationChanged(Location 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 IBinder onBind(Intent arg0) {
    return null;
}

}

此代码放在oncreate方法

中的活动中

GPSTracker gps;
gps = new GPSTracker(NearMeActivity.this);

    if (gps.canGetLocation()) {

        latitude = gps.getLatitude();
        longitude = gps.getLongitude();

        // Toast.makeText(
        // getApplicationContext(),
        // "Your Location is - \nLat: " + latitude + "\nLong: "
        // + longitude, Toast.LENGTH_LONG).show();
    } else {
        gps.showSettingsAlert();
    }

    Log.e("latlong", "" + latitude + "" + longitude);

Answer 3

使用google map api v2

例如

   public class MapActivity extends FragmentActivity {
protected GoogleMap map;
protected LatLng start;
protected LatLng end;
TextView tvDistance,tvTime;
CameraPosition mCameraPosition;
    //   LatLng currentLocation ;
Context context;
public static boolean loadMapChk = false;
double getlatitute, getlongitute;
String addressGeo;
/**
 * This activity loads a map and then displays the route and pushpins on it.
 */
@Override 
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.map);
    context = this;

    Bundle bundle = getIntent().getExtras();
    if (bundle != null) {

        getlatitute = bundle.getDouble("getlatitute");
        getlongitute = bundle.getDouble("getlongitute");
        addressGeo = bundle.getString("addressGeo");
    }


    tvDistance = (TextView) findViewById(R.id.tvDistance);
    tvTime = (TextView) findViewById(R.id.tvTime);

    SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
    map = fm.getMap();

    map.setMyLocationEnabled(true);
    map.setOnMyLocationChangeListener(myLocationChangeListener);




}
private GoogleMap.OnMyLocationChangeListener myLocationChangeListener = new GoogleMap.OnMyLocationChangeListener() {
    @Override
    public void onMyLocationChange (Location location) {
       LatLng loc = new LatLng (location.getLatitude(), location.getLongitude());

//  Toast.makeText(getApplicationContext(),"location.getLongitude()>>>>>>>"+location.getLongitude(),Toast.LENGTH_LONG).show();

     //  map.animateCamera(CameraUpdateFactory.newLatLngZoom(loc, 16.0f));
       Bitmap bitmapicon = BitmapFactory.decodeResource(context.getResources(),
               R.drawable.start_blue);
       map.addMarker(new MarkerOptions().position(
               new LatLng(location.getLatitude(), location.getLongitude())).title("My Location").icon(BitmapDescriptorFactory.fromBitmap(bitmapicon)));

       if (!loadMapChk)
       {       
       map.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 12.5f), 4000, null);
       loadMapChk = true;
       }
       start = new LatLng(location.getLatitude(), location.getLongitude());
       end = new LatLng(getlatitute, getlongitute);

       Bitmap bitmapiconEnd = BitmapFactory.decodeResource(context.getResources(),
               R.drawable.end_green);
       map.addMarker(new MarkerOptions().position(
               new LatLng(getlatitute, getlongitute)).title(addressGeo).icon(BitmapDescriptorFactory.fromBitmap(bitmapiconEnd)));

       Routing routing = new Routing(Routing.TravelMode.DRIVING);
       routing.registerListener(routingListener);
       routing.execute(start, end);


    }
};


@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    loadMapChk = false;
}

      public  RoutingListener routingListener = new RoutingListener() {

@Override
public void onRoutingSuccess(PolylineOptions mPolyOptions, Route route) {
      PolylineOptions polyOptions = new PolylineOptions();
        polyOptions.color(Color.CYAN);
        polyOptions.width(8);
        polyOptions.addAll(mPolyOptions.getPoints());
        tvDistance.setText("Distance : "+route.getDistanceText());
        tvTime.setText("Time : "+route.getDurationText());
      //  Toast.makeText(getApplicationContext(), "Distance : "+route.getDistanceText()+" & Time = "+route.getDurationText(),6).show();
        map.addPolyline(polyOptions);

        // Start marker
        MarkerOptions options = new MarkerOptions();


        // End marker
        options = new MarkerOptions();
        options.position(end);
        options.icon(BitmapDescriptorFactory.fromResource(R.drawable.end_green));
        map.addMarker(options);     
}

@Override
public void onRoutingStart() {
    // TODO Auto-generated method stub

}

@Override
public void onRoutingFailure() {
    // TODO Auto-generated method stub

}

};

}

Answer 4

使用timer handeller实现延迟。

 Total time= Time delay+ Server response

你可能因为那个而面临问题

20秒后获得地理定位

4 个答案: