Android上的LocationManager API似乎对一个只需要偶尔粗略估计用户位置的应用程序来说有点麻烦。
我正在开发的应用程序本身并不是一个定位应用程序，但它确实需要获取用户的位置，以便显示附近企业的列表。它不需要担心用户是否在移动或类似的事情。
以下是我想做的：
向用户显示附近位置的列表。预加载用户的位置，以便在“活动X”中需要它时，它将可用。我并不特别关心更新的准确性或频率。只要不太远，只要抓住一个位置就足够了。也许如果我想变得更漂亮，我会每隔几分钟左右更新一次位置，但这不是一个很大的优先事项。适用于任何具有GPS或网络位置提供商的设备。
这似乎并不难，但在我看来，我必须组建两个不同的位置提供商（GPS和NETWORK），并管理每个提供商的生命周期。不仅如此，我还必须在多个活动中复制相同的代码以满足#2。过去，我曾尝试使用getBestProvider（）将解决方案简化为仅使用一个位置提供程序，但这似乎只提供了最好的“理论”提供程序，而不是实际会为您提供最佳结果的提供程序。
有没有更简单的方法来实现这一点？
当前回答
我已经创建了一个小应用程序，并逐步描述以获取当前位置GPS坐标。
以下URL中的完整示例源代码：
获取当前位置坐标，城市名称-在Android中
查看其工作原理：
我们只需要在清单文件中添加此权限<uses permission android:name=“android.permission.ACCESS_FINE_LOCATION”></使用权限>并像这样创建LocationManager实例LocationManager LocationManager=（LocationManager）getSystemService（Context.LOCATION_SERVICE）；检查GPS是否已启用然后实现LocationListener和Get CoordinatesLocationListener LocationListener=新的MyLocationListeners（）；locationManager.requestLocationUpdates（LocationManager.GPS_PROVIDER，5000，10，locationListener）；下面是要做的示例代码
/*----------Listener class to get coordinates ------------- */
private class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location loc) {
editLocation.setText("");
pb.setVisibility(View.INVISIBLE);
Toast.makeText(
getBaseContext(),
"Location changed: Lat: " + loc.getLatitude() + " Lng: "
+ loc.getLongitude(), Toast.LENGTH_SHORT).show();
String longitude = "Longitude: " + loc.getLongitude();
Log.v(TAG, longitude);
String latitude = "Latitude: " + loc.getLatitude();
Log.v(TAG, latitude);
/*-------to get City-Name from coordinates -------- */
String cityName = null;
Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
List<Address> addresses;
try {
addresses = gcd.getFromLocation(loc.getLatitude(),
loc.getLongitude(), 1);
if (addresses.size() > 0)
System.out.println(addresses.get(0).getLocality());
cityName = addresses.get(0).getLocality();
} catch (IOException e) {
e.printStackTrace();
}
String s = longitude + "\n" + latitude + "\n\nMy Current City is: "
+ cityName;
editLocation.setText(s);
}
@Override
public void onProviderDisabled(String provider) {}
@Override
public void onProviderEnabled(String provider) {}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
其他回答
在搜索了如何获得最佳精确用户位置的最佳实现后，我成功地结合了所有最佳方法，并提出了以下类：
/**
* Retrieve accurate location from GPS or network services.
*
*
* Class usage example:
*
* public void onCreate(Bundle savedInstanceState) {
* ...
* my_location = new MyLocation();
* my_location.init(main.this, locationResult);
* }
*
*
* public LocationResult locationResult = new LocationResult(){
* @Override
* public void gotLocation(final Location location){
* // do something
* location.getLongitude();
* location.getLatitude();
* }
* };
*/
class MyLocation{
/**
* If GPS is enabled.
* Use minimal connected satellites count.
*/
private static final int min_gps_sat_count = 5;
/**
* Iteration step time.
*/
private static final int iteration_timeout_step = 500;
LocationResult locationResult;
private Location bestLocation = null;
private Handler handler = new Handler();
private LocationManager myLocationManager;
public Context context;
private boolean gps_enabled = false;
private int counts = 0;
private int sat_count = 0;
private Runnable showTime = new Runnable() {
public void run() {
boolean stop = false;
counts++;
System.println("counts=" + counts);
//if timeout (1 min) exceeded, stop tying
if(counts > 120){
stop = true;
}
//update last best location
bestLocation = getLocation(context);
//if location is not ready or don`t exists, try again
if(bestLocation == null && gps_enabled){
System.println("BestLocation not ready, continue to wait");
handler.postDelayed(this, iteration_timeout_step);
}else{
//if best location is known, calculate if we need to continue to look for better location
//if gps is enabled and min satellites count has not been connected or min check count is smaller then 4 (2 sec)
if(stop == false && !needToStop()){
System.println("Connected " + sat_count + " sattelites. continue waiting..");
handler.postDelayed(this, iteration_timeout_step);
}else{
System.println("#########################################");
System.println("BestLocation found return result to main. sat_count=" + sat_count);
System.println("#########################################");
// removing all updates and listeners
myLocationManager.removeUpdates(gpsLocationListener);
myLocationManager.removeUpdates(networkLocationListener);
myLocationManager.removeGpsStatusListener(gpsStatusListener);
sat_count = 0;
// send best location to locationResult
locationResult.gotLocation(bestLocation);
}
}
}
};
/**
* Determine if continue to try to find best location
*/
private Boolean needToStop(){
if(!gps_enabled){
return true;
}
else if(counts <= 4){
return false;
}
if(sat_count < min_gps_sat_count){
//if 20-25 sec and 3 satellites found then stop
if(counts >= 40 && sat_count >= 3){
return true;
}
return false;
}
}
return true;
}
/**
* Best location abstract result class
*/
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
/**
* Initialize starting values and starting best location listeners
*
* @param Context ctx
* @param LocationResult result
*/
public void init(Context ctx, LocationResult result){
context = ctx;
locationResult = result;
myLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
gps_enabled = (Boolean) myLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
bestLocation = null;
counts = 0;
// turning on location updates
myLocationManager.requestLocationUpdates("network", 0, 0, networkLocationListener);
myLocationManager.requestLocationUpdates("gps", 0, 0, gpsLocationListener);
myLocationManager.addGpsStatusListener(gpsStatusListener);
// starting best location finder loop
handler.postDelayed(showTime, iteration_timeout_step);
}
/**
* GpsStatus listener. OnChainged counts connected satellites count.
*/
public final GpsStatus.Listener gpsStatusListener = new GpsStatus.Listener() {
public void onGpsStatusChanged(int event) {
if(event == GpsStatus.GPS_EVENT_SATELLITE_STATUS){
try {
// Check number of satellites in list to determine fix state
GpsStatus status = myLocationManager.getGpsStatus(null);
Iterable<GpsSatellite>satellites = status.getSatellites();
sat_count = 0;
Iterator<GpsSatellite>satI = satellites.iterator();
while(satI.hasNext()) {
GpsSatellite satellite = satI.next();
System.println("Satellite: snr=" + satellite.getSnr() + ", elevation=" + satellite.getElevation());
sat_count++;
}
} catch (Exception e) {
e.printStackTrace();
sat_count = min_gps_sat_count + 1;
}
System.println("#### sat_count = " + sat_count);
}
}
};
/**
* Gps location listener.
*/
public final LocationListener gpsLocationListener = new LocationListener(){
@Override
public void onLocationChanged(Location location){
}
public void onProviderDisabled(String provider){}
public void onProviderEnabled(String provider){}
public void onStatusChanged(String provider, int status, Bundle extras){}
};
/**
* Network location listener.
*/
public final LocationListener networkLocationListener = new LocationListener(){
@Override
public void onLocationChanged(Location location){
}
public void onProviderDisabled(String provider){}
public void onProviderEnabled(String provider){}
public void onStatusChanged(String provider, int status, Bundle extras){}
};
/**
* Returns best location using LocationManager.getBestProvider()
*
* @param context
* @return Location|null
*/
public static Location getLocation(Context context){
System.println("getLocation()");
// fetch last known location and update it
try {
LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
String strLocationProvider = lm.getBestProvider(criteria, true);
System.println("strLocationProvider=" + strLocationProvider);
Location location = lm.getLastKnownLocation(strLocationProvider);
if(location != null){
return location;
}
return null;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
如果启用gps，此类将尝试连接到min_gps_sat_count卫星。Else返回LocationManager.getBestProvider（）位置。检查代码！
这是提供用户当前位置的代码
创建地图活动：
public class Maps extends MapActivity {
public static final String TAG = "MapActivity";
private MapView mapView;
private LocationManager locationManager;
Geocoder geocoder;
Location location;
LocationListener locationListener;
CountDownTimer locationtimer;
MapController mapController;
MapOverlay mapOverlay = new MapOverlay();
@Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
initComponents();
mapView.setBuiltInZoomControls(true);
mapView.setSatellite(true);
mapView.setTraffic(true);
mapView.setStreetView(true);
mapController = mapView.getController();
mapController.setZoom(16);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (locationManager == null) {
Toast.makeText(Maps.this, "Location Manager Not Available",
Toast.LENGTH_SHORT).show();
return;
}
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location == null)
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
double lat = location.getLatitude();
double lng = location.getLongitude();
Toast.makeText(Maps.this, "Location Are" + lat + ":" + lng,
Toast.LENGTH_SHORT).show();
GeoPoint point = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
mapController.animateTo(point, new Message());
mapOverlay.setPointToDraw(point);
List<Overlay> listOfOverlays = mapView.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
}
locationListener = new LocationListener() {
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}
public void onProviderEnabled(String arg0) {}
public void onProviderDisabled(String arg0) {}
public void onLocationChanged(Location l) {
location = l;
locationManager.removeUpdates(this);
if (l.getLatitude() == 0 || l.getLongitude() == 0) {
} else {
double lat = l.getLatitude();
double lng = l.getLongitude();
Toast.makeText(Maps.this, "Location Are" + lat + ":" + lng,
Toast.LENGTH_SHORT).show();
}
}
};
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 10f, locationListener);
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 1000, 10f, locationListener);
locationtimer = new CountDownTimer(30000, 5000) {
@Override
public void onTick(long millisUntilFinished) {
if (location != null) locationtimer.cancel();
}
@Override
public void onFinish() {
if (location == null) {
}
}
};
locationtimer.start();
}
public MapView getMapView() {
return this.mapView;
}
private void initComponents() {
mapView = (MapView) findViewById(R.id.map_container);
ImageView ivhome = (ImageView) this.findViewById(R.id.imageView_home);
ivhome.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent = new Intent(Maps.this, GridViewContainer.class);
startActivity(intent);
finish();
}
});
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
class MapOverlay extends Overlay {
private GeoPoint pointToDraw;
public void setPointToDraw(GeoPoint point) {
pointToDraw = point;
}
public GeoPoint getPointToDraw() {
return pointToDraw;
}
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
long when) {
super.draw(canvas, mapView, shadow);
Point screenPts = new Point();
mapView.getProjection().toPixels(pointToDraw, screenPts);
Bitmap bmp = BitmapFactory.decodeResource(getResources(),
R.drawable.select_map);
canvas.drawBitmap(bmp, screenPts.x, screenPts.y - 24, null);
return true;
}
}
}
main.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/black"
android:orientation="vertical" >
<com.google.android.maps.MapView
android:id="@+id/map_container"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:apiKey="yor api key"
android:clickable="true"
android:focusable="true" />
</LinearLayout>
并在清单中定义以下权限：
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
最近进行了重构以获得代码的位置，学习了一些好的想法，最终实现了一个相对完善的库和演示。
//request all valid provider(network/gps)
private boolean requestAllProviderUpdates() {
checkRuntimeEnvironment();
checkPermission();
if (isRequesting) {
EasyLog.d("Request location update is busy");
return false;
}
long minTime = getCheckTimeInterval();
float minDistance = getCheckMinDistance();
if (mMapLocationListeners == null) {
mMapLocationListeners = new HashMap<>();
}
mValidProviders = getValidProviders();
if (mValidProviders == null || mValidProviders.isEmpty()) {
throw new IllegalArgumentException("Not available provider.");
}
for (String provider : mValidProviders) {
LocationListener locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
if (location == null) {
EasyLog.e("LocationListener callback location is null.");
return;
}
printf(location);
mLastProviderTimestamp = location.getTime();
if (location.getProvider().equals(LocationManager.GPS_PROVIDER)) {
finishResult(location);
} else {
doLocationResult(location);
}
removeProvider(location.getProvider());
if (isEmptyValidProviders()) {
requestTimeoutMsgInit();
removeUpdates();
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
};
getLocationManager().requestLocationUpdates(provider, minTime, minDistance, locationListener);
mMapLocationListeners.put(provider, locationListener);
EasyLog.d("Location request %s provider update.", provider);
}
isRequesting = true;
return true;
}
//remove request update
public void removeUpdates() {
checkRuntimeEnvironment();
LocationManager locationManager = getLocationManager();
if (mMapLocationListeners != null) {
Set<String> keys = mMapLocationListeners.keySet();
for (String key : keys) {
LocationListener locationListener = mMapLocationListeners.get(key);
if (locationListener != null) {
locationManager.removeUpdates(locationListener);
EasyLog.d("Remove location update, provider is " + key);
}
}
mMapLocationListeners.clear();
isRequesting = false;
}
}
//Compared with the last successful position, to determine whether you need to filter
private boolean isNeedFilter(Location location) {
checkLocation(location);
if (mLastLocation != null) {
float distance = location.distanceTo(mLastLocation);
if (distance < getCheckMinDistance()) {
return true;
}
if (location.getAccuracy() >= mLastLocation.getAccuracy()
&& distance < location.getAccuracy()) {
return true;
}
if (location.getTime() <= mLastProviderTimestamp) {
return true;
}
}
return false;
}
private void doLocationResult(Location location) {
checkLocation(location);
if (isNeedFilter(location)) {
EasyLog.d("location need to filtered out, timestamp is " + location.getTime());
finishResult(mLastLocation);
} else {
finishResult(location);
}
}
//Return to the finished position
private void finishResult(Location location) {
checkLocation(location);
double latitude = location.getLatitude();
double longitude = location.getLongitude();
float accuracy = location.getAccuracy();
long time = location.getTime();
String provider = location.getProvider();
if (mLocationResultListeners != null && !mLocationResultListeners.isEmpty()) {
String format = "Location result:<%f, %f> Accuracy:%f Time:%d Provider:%s";
EasyLog.i(String.format(format, latitude, longitude, accuracy, time, provider));
mLastLocation = location;
synchronized (this) {
Iterator<LocationResultListener> iterator = mLocationResultListeners.iterator();
while (iterator.hasNext()) {
LocationResultListener listener = iterator.next();
if (listener != null) {
listener.onResult(location);
}
iterator.remove();
}
}
}
}
完整代码：https://github.com/bingerz/FastLocation/blob/master/fastlocationlib/src/main/java/cn/bingerz/fastlocation/FastLocation.java
*每次请求完成位置时，最好删除更新，否则手机状态栏将始终显示定位图标。
我已经创建了一个小应用程序，并逐步描述以获取当前位置GPS坐标。
以下URL中的完整示例源代码：
获取当前位置坐标，城市名称-在Android中
查看其工作原理：
我们只需要在清单文件中添加此权限<uses permission android:name=“android.permission.ACCESS_FINE_LOCATION”></使用权限>并像这样创建LocationManager实例LocationManager LocationManager=（LocationManager）getSystemService（Context.LOCATION_SERVICE）；检查GPS是否已启用然后实现LocationListener和Get CoordinatesLocationListener LocationListener=新的MyLocationListeners（）；locationManager.requestLocationUpdates（LocationManager.GPS_PROVIDER，5000，10，locationListener）；下面是要做的示例代码
/*----------Listener class to get coordinates ------------- */
private class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location loc) {
editLocation.setText("");
pb.setVisibility(View.INVISIBLE);
Toast.makeText(
getBaseContext(),
"Location changed: Lat: " + loc.getLatitude() + " Lng: "
+ loc.getLongitude(), Toast.LENGTH_SHORT).show();
String longitude = "Longitude: " + loc.getLongitude();
Log.v(TAG, longitude);
String latitude = "Latitude: " + loc.getLatitude();
Log.v(TAG, latitude);
/*-------to get City-Name from coordinates -------- */
String cityName = null;
Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
List<Address> addresses;
try {
addresses = gcd.getFromLocation(loc.getLatitude(),
loc.getLongitude(), 1);
if (addresses.size() > 0)
System.out.println(addresses.get(0).getLocality());
cityName = addresses.get(0).getLocality();
} catch (IOException e) {
e.printStackTrace();
}
String s = longitude + "\n" + latitude + "\n\nMy Current City is: "
+ cityName;
editLocation.setText(s);
}
@Override
public void onProviderDisabled(String provider) {}
@Override
public void onProviderEnabled(String provider) {}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
在android系统中获取位置更新需要很多东西，需要大量的bolierplate代码。
你需要照顾好
Google Play服务可用性检查，更新Google play服务，如果它是旧的或不可用GoogleApiClient的对话框创建及其连接、断开等回调。停止并释放用于位置更新的资源处理位置权限方案检查位置服务是否打开或关闭获取最新位置也不是那么容易如果在一定时间后未找到位置，则回退到最后一个已知位置
我已经创建了Android EasyLocation（小型Android库），它将处理所有这些事情，您可以专注于业务逻辑。
您只需要扩展EasyLocationActivity
requestSingleLocationFix(easyLocationRequest);
or
requestLocationUpdates(easyLocationRequest);
点击此处查看示例应用程序和所需步骤https://github.com/akhgupta/Android-EasyLocation
