我正在尝试创建一个显示我当前位置的应用 我有所有必要的许可， 我有另一个类名GPS跟踪器来获取我的GPS位置
继承我的代码：
GPSTracker gpsTracker = new GPSTracker(this);
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
map.setMapType(GoogleMap.MAP_TYPE_NORMAL);
latitude = gpsTracker.latitude;
longitude = gpsTracker.longitude;
LatLng latLng = new LatLng(latitude, longitude);
map.moveCamera(CameraUpdateFactory.newLatLng(latLng));
map.animateCamera(CameraUpdateFactory.zoomTo(18));
这是GPSTracker课程：
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;
}
}
答案 0 :(得分：4)
请勿使用GPS跟踪器类。它非常可怕地被打破了。在很多方面，我今晚写了一篇关于它的长篇博文：见http://gabesechansoftware.com/location-tracking/
以下是破碎的方式：
1）它不跟踪GPS。有时它会跟踪网络位置
2）canGetLocation功能被破坏。它在有位置之前返回true
3）它非常低效，迫使你进行民意调查。
4）它没有将陈旧与新鲜数据区分开来 - 也不允许你这样做
我会继续，但我已经在今晚写完了。
我在博客上写了一个更好的GPS跟踪器库。在这里重复使用SO
LocationTracker.java
package com.gabesechan.android.reusable.location;
import android.location.Location;
public interface LocationTracker {
public interface LocationUpdateListener{
public void onUpdate(Location oldLoc, long oldTime, Location newLoc, long newTime);
}
public void start();
public void start(LocationUpdateListener update);
public void stop();
public boolean hasLocation();
public boolean hasPossiblyStaleLocation();
public Location getLocation();
public Location getPossiblyStaleLocation();
}
ProviderLocationTracker.java
package com.gabesechan.android.reusable.location;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
public class ProviderLocationTracker implements LocationListener, LocationTracker {
// The minimum distance to change Updates in meters
private static final long MIN_UPDATE_DISTANCE = 10;
// The minimum time between updates in milliseconds
private static final long MIN_UPDATE_TIME = 1000 * 60;
private LocationManager lm;
public enum ProviderType{
NETWORK,
GPS
};
private String provider;
private Location lastLocation;
private long lastTime;
private boolean isRunning;
private LocationUpdateListener listener;
public ProviderLocationTracker(Context context, ProviderType type) {
lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
if(type == ProviderType.NETWORK){
provider = LocationManager.NETWORK_PROVIDER;
}
else{
provider = LocationManager.GPS_PROVIDER;
}
}
public void start(){
if(isRunning){
//Already running, do nothing
return;
}
//The provider is on, so start getting updates. Update current location
isRunning = true;
lm.requestLocationUpdates(provider, MIN_UPDATE_TIME, MIN_UPDATE_DISTANCE, this);
lastLocation = null;
lastTime = 0;
return;
}
public void start(LocationUpdateListener update) {
start();
listener = update;
}
public void stop(){
if(isRunning){
lm.removeUpdates(this);
isRunning = false;
listener = null;
}
}
public boolean hasLocation(){
if(lastLocation == null){
return false;
}
if(System.currentTimeMillis() - lastTime > 5 * MIN_UPDATE_TIME){
return false; //stale
}
return true;
}
public boolean hasPossiblyStaleLocation(){
if(lastLocation != null){
return true;
}
return lm.getLastKnownLocation(provider)!= null;
}
public Location getLocation(){
if(lastLocation == null){
return null;
}
if(System.currentTimeMillis() - lastTime > 5 * MIN_UPDATE_TIME){
return null; //stale
}
return lastLocation;
}
public Location getPossiblyStaleLocation(){
if(lastLocation != null){
return lastLocation;
}
return lm.getLastKnownLocation(provider);
}
public void onLocationChanged(Location newLoc) {
long now = System.currentTimeMillis();
if(listener != null){
listener.onUpdate(lastLocation, lastTime, newLoc, now);
}
lastLocation = newLoc;
lastTime = now;
}
public void onProviderDisabled(String arg0) {
}
public void onProviderEnabled(String arg0) {
}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
}
}
FallbackLocationTracker.java
package com.gabesechan.android.reusable.location;
import android.content.Context;
import android.location.Location;
import android.location.LocationManager;
public class FallbackLocationTracker implements LocationTracker, LocationTracker.LocationUpdateListener {
private boolean isRunning;
private ProviderLocationTracker gps;
private ProviderLocationTracker net;
private LocationUpdateListener listener;
Location lastLoc;
long lastTime;
public FallbackLocationTracker(Context context, ProviderLocationTracker.ProviderType type) {
gps = new ProviderLocationTracker(context, ProviderLocationTracker.ProviderType.GPS);
net = new ProviderLocationTracker(context, ProviderLocationTracker.ProviderType.NETWORK);
}
public void start(){
if(isRunning){
//Already running, do nothing
return;
}
//Start both
gps.start(this);
net.start(this);
isRunning = true;
}
public void start(LocationUpdateListener update) {
start();
listener = update;
}
public void stop(){
if(isRunning){
gps.stop();
net.stop();
isRunning = false;
listener = null;
}
}
public boolean hasLocation(){
//If either has a location, use it
return gps.hasLocation() || net.hasLocation();
}
public boolean hasPossiblyStaleLocation(){
//If either has a location, use it
return gps.hasPossiblyStaleLocation() || net.hasPossiblyStaleLocation();
}
public Location getLocation(){
Location ret = gps.getLocation();
if(ret == null){
ret = net.getLocation();
}
return ret;
}
public Location getPossiblyStaleLocation(){
Location ret = gps.getPossiblyStaleLocation();
if(ret == null){
ret = net.getPossiblyStaleLocation();
}
return ret;
}
public void onUpdate(Location oldLoc, long oldTime, Location newLoc, long newTime) {
boolean update = false;
//We should update only if there is no last location, the provider is the same, or the provider is more accurate, or the old location is stale
if(lastLoc == null){
update = true;
}
else if(lastLoc != null && lastLoc.getProvider().equals(newLoc.getProvider())){
update = true;
}
else if(newLoc.getProvider().equals(LocationManager.GPS_PROVIDER)){
update = true;
}
else if (newTime - lastTime > 5 * 60 * 1000){
update = true;
}
if(update){
lastLoc = newLoc;
lastTime = newTime;
if(listener != null){
listener.onUpdate(lastLoc, lastTime, newLoc, newTime);
}
}
}
}
界面定义了一个通用位置跟踪器，因此您可以在它们之间切换。 ProviderLocationTracker将允许您通过GPS或网络进行跟踪，具体取决于您传递给其构造函数的参数。 FallbackLocationTracker将通过两者进行跟踪，仅为您提供当前可用的最准确信息，但如果GPS尚未就绪，则会退回到网络。
答案 1 :(得分：0)
使用此代码
并从“implements LocationListener”
实现您的活动locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,3000, // 3 sec
5, this);
boolean isGPS = locationManager.isProviderEnabled (LocationManager.GPS_PROVIDER);
if(!isGPS)
{
showSettingsAlert();
GPS_imageview.setBackgroundResource(R.drawable.gpsnonfix);
//Toast.makeText(getApplicationContext(), "Please Start GPS to get more Accurate location", Toast.LENGTH_SHORT) .show();
}
并使用以下
@Override
public void onLocationChanged(Location location) {
int a=location.getExtras().getInt("satellites") ;
if(a>4)
{
String str = "Latitude: "+location.getLatitude()+" \nLongitude: "+location.getLongitude();
// Toast.makeText(getBaseContext(), str, Toast.LENGTH_LONG).show();
Double lat=location.getLatitude();
Double lan=location.getLongitude();
}else{
}
String str = "Latitude: "+location.getLatitude()+" \nLongitude: "+location.getLongitude();
Toast.makeText(getBaseContext(), str, Toast.LENGTH_LONG).show();
}
@Override
public void onProviderDisabled(String provider) {
/******** Called when User off Gps *********/
Latitude="0.0";
Longitude="0.0";
Toast.makeText(getBaseContext(), "Gps turned off ", Toast.LENGTH_LONG).show();
}
@Override
public void onProviderEnabled(String provider) {
/******** Called when User on Gps *********/
Toast.makeText(getBaseContext(), "Gps turned on ", Toast.LENGTH_LONG).show();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
这个代码得不到卫星。如果没有卫星比4更好，那么得到适当的结果......结果的准确性很好......
答案 2 :(得分：0)
当您启动应用时，您的GPS可能尚未建立连接并为您提供默认位置，例如0,0。如果您的手机在以后找到其坐标，则您的应用无法检测到此情况。
这一行：
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
指出每次手机发现位置更改时，都会调用＆＃34; OnLocationChanged＆＃34; -method（您调用该行代码的对象）。据我所知，你还没有实现这个方法。
我建议如下。将第三行更改为： lm.requestLocationUpdates（LocationManager.NETWORK_PROVIDER，0,0，gpsTracker）;
因此它使用了gpsTracker的onLocationChanged方法的实现。 现在，实现您已经定义但尚未实现的GPSTracker类的OnLocationChanged方法：
@Override
public void onLocationChanged(Location location) {
//This method is triggered every time your location changes.
//The 'location' argument can be used to access the current location.
}