如何更好地处理 GPS 位置和 android

Posted 2023-04-14

【中文标题】如何更好地处理 GPS 位置和 android

【英文标题】：How to better handle GPS location and android

【发布时间】：2014-04-15 15:41:48

【问题描述】：

我有一个带有列表视图的片段，它检索用户位置，然后根据用户位置更新列表视图。

我的代码的问题是它似乎抓住了位置更新列表，然后继续更新。并重新加载列表，几乎到了烦恼的地步。这是我的代码：

public class FindBrewery extends Fragment implements LocationListener 

    private TextView latituteField;
    private TextView longitudeField;
    LocationManager locationManager;
    private String provider;


    @Override
    public void onAttach(Activity activity) 
        super.onAttach(activity);
        Context c = getActivity().getApplicationContext();
        locationManager =(LocationManager)activity.getSystemService(Context.LOCATION_SERVICE);

    



    public void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);

    

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) 
        //todo change view
        View rootView = inflater.inflate(R.layout.beer_location_list,container, false);

        // Get the location manager
        // Define the criteria how to select the locatioin provider -> use
        // default
        Criteria criteria = new Criteria();
        provider = locationManager.getBestProvider(criteria, false);
        Location location = locationManager.getLastKnownLocation(provider);

        // Initialize the location fields
        if (location != null) 
            System.out.println("Provider " + provider + " has been selected.");
            onLocationChanged(location);
         else 

        


        return rootView;
    




    /* Request updates at startup */
    @Override
    public void onResume() 
        super.onResume();
        locationManager.requestLocationUpdates(provider, 400, 1, this);
    

    /* Remove the locationlistener updates when Activity is paused */
    @Override
    public void onPause() 
        super.onPause();
        locationManager.removeUpdates(this);
    

    @Override
    public void onLocationChanged(Location location) 
        int lat = (int) (location.getLatitude());
        int lng = (int) (location.getLongitude());
        //latituteField.setText(String.valueOf(lat));
        //longitudeField.setText(String.valueOf(lng));

        //Toast.makeText(this, "Finding your loaction",Toast.LENGTH_SHORT).show();

        //call asycn task for location
        String url = "myURL";

        Log.d("urlTest", url);

        //async task goes here
        new GetNearbyBreweries(this.getActivity()).execute(url);



    

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) 
        // TODO Auto-generated method stub

    

    @Override
    public void onProviderEnabled(String provider) 
        //Toast.makeText(this, "Enabled new provider " + provider,Toast.LENGTH_SHORT).show();

    

    @Override
    public void onProviderDisabled(String provider) 
        //Toast.makeText(this, "Disabled provider " + provider,Toast.LENGTH_SHORT).show();
    

【参考方案1】：

也许你想试试这个方法：

LocationClient mLocationClient;
LocationRequest mLocationRequest;

@Override
public void onAttach(Activity activity) 
  if (GooglePlayServicesUtil.isGooglePlayServicesAvailable(activity)) 
    mLocationClient = new LocationClient(activity, activity, activity);

    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequest.setInterval(5000);
    mLocationRequest.setNumUpdates(1);
    mLocationRequest.setFastestInterval(1000);
  


@Override
public void onActivityCreated(Bundle savedInstanceState) 
  if (mLocationClient != null) 
    mLocationClient.connect();
  


@Override
protected void onStop() 
  if (mLocationClient != null) 
    if (mLocationClient.isConnected()) 
      mLocationClient.removeLocationUpdates(this);
    

    mLocationClient.disconnect();
  
  super.onStop();


@Override
public void onConnected(Bundle dataBundle) 
  LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
  mLocationClient.requestLocationUpdates(mLocationRequest, this);


@Override
public void onLocationChanged(Location location) 
  int lat = (int) (location.getLatitude());
  int lng = (int) (location.getLongitude());

  // post to a handler to update the list items

诀窍如下：

您不要使用 getLastKnownLocation，因为它使用缓存并且经常返回错误数据， 你设置了setNumUpdates(1)，所以你

不需要

打电话给removeLocationUpdates()

不要忘记 androidManifest 权限：

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

【讨论】：

我在上面的代码中哪里调用了我的异步任务，一旦它有了位置？

如您所见：滚动代码框以查看 :) 让我知道这是否适合您。

【参考方案2】：

Here 是一篇关于 GPS 位置以及如何经常检查它的巨大帖子。 （在该示例中为 30 分钟）

您可能还想查看Timer 以设置对方法的重复调用，该方法以您想要的时间间隔获取位置。

【参考方案3】：

虽然它可能有点满足您的需求，但请查看 Fused Location Provider。就 Android 中的位置管理器而言，它是相当具有革命性的。它允许您执行某些操作，例如设置最大和最小间隔时间以及非常直接的关闭实现。我从这个示例进行了第一次运行，效果非常好（我试图做相反的事情，我需要每 5 秒更新一次，而 Android 每 30-45 秒进行一次更新）：

http://www.kpbird.com/2013/06/fused-location-provider-example.html

【参考方案4】：

您应该从代码中某处的 gps 中删除更新（假设在您的情况下，当您从用户那里获得当前位置时您可能会这样做），因此调用 locationManager.removeUpdates(this);一旦你有一个适合你需要的位置，就在 onLocationChanged() 方法中。

【参考方案5】：

为此，我使用了一项单独的服务，并在其中实现了 GPS 相关功能。该服务发出位置请求并将其广播回来。所以你可以只注册接收器来获取接收到的坐标。

LocationService.java

package com.my.package.services;

import android.app.Service;
import android.content.Intent;
import android.location.Location;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient.ConnectionCallbacks;
import com.google.android.gms.common.GooglePlayServicesClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;


public class LocationService extends Service implements LocationListener, ConnectionCallbacks, OnConnectionFailedListener 
    private static final String TAG = LocationService.class.getSimpleName();

    public static final String BROADCAST_ACTION = "com.my.package.LOCATION_UPDATE";

    // Milliseconds per second
    private static final int MILLISECONDS_PER_SECOND = 1000;

    // Update frequency in seconds
    public static final int UPDATE_INTERVAL_IN_SECONDS = 60;

    // Update frequency in milliseconds
    private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;

    // The fastest update frequency, in seconds
    private static final int FASTEST_INTERVAL_IN_SECONDS = 40;

    // A fast frequency ceiling in milliseconds
    private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;

    private LocationClient locationClient;

    @Override
    public void onCreate() 
        super.onCreate();

        Log.d(TAG, "Location service created…");

        locationClient = new LocationClient(this, this, this);
        locationClient.connect();
    

    // Unregister location listeners
    private void clearLocationData() 
        locationClient.disconnect();

        if (locationClient.isConnected()) 
            locationClient.removeLocationUpdates(this);
        
    

    @Override
    public IBinder onBind(Intent intent) 
        return null;
    


    // When service destroyed we need to unbind location listeners
    @Override
    public void onDestroy() 
        super.onDestroy();

        Log.d(TAG, "Location service destroyed…");

        clearLocationData();
    

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) 
        Log.d(TAG, "Calling command…");

        return START_STICKY;
    

    @Override
    public void onConnected(Bundle bundle) 
        Log.d(TAG, "Location Callback. onConnected");

        Location currentLocation = locationClient.getLastLocation();

        // Create the LocationRequest object
        LocationRequest locationRequest = LocationRequest.create();

        // Use power balanced mode
        locationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);

        // Set the update interval to 5 seconds
        locationRequest.setInterval(UPDATE_INTERVAL);

        // Set the fastest update interval to 1 second
        locationRequest.setFastestInterval(FASTEST_INTERVAL);

        locationClient.requestLocationUpdates(locationRequest, this);

        onLocationChanged(currentLocation);
    

    @Override
    public void onLocationChanged(Location location) 
        Log.d(TAG, "onLocationChanged");
        Log.d(TAG, "LOCATION: " + location.getLatitude() + ":" + location.getLongitude());

        // Since location information updated, broadcast it
        Intent broadcast = new Intent();

        // Set action so other parts of application can distinguish and use this information if needed
        broadcast.setAction(BROADCAST_ACTION);
        broadcast.putExtra("latitude", location.getLatitude());
        broadcast.putExtra("longitude", location.getLongitude());

        sendBroadcast(broadcast);
    

    @Override
    public void onDisconnected() 
        Log.d(TAG, "Location Callback. onDisconnected");
    

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) 
        Log.d(TAG, "Location Callback. onConnectionFailed");