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

建议使用LocationClient:

首先,定义位置更新间隔值。根据您的需要进行调整。

private static final int MILLISECONDS_PER_SECOND = 1000;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;

让您的活动实现GooglePlayServicesClient.ConnectionCallbacks、GooglePlayServicesClient OnConnectionFailedListener和LocationListener。

public class LocationActivity extends Activity implements 
GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {}

然后,在Activity的onCreate()方法中设置LocationClient:

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

    mLocationClient = new LocationClient(this, this, this);

    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequest.setInterval(UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}

将所需方法添加到“活动”中;onConnected()是LocationClient连接时调用的方法。onLocationChanged()是检索最新位置的位置。

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Log.w(TAG, "Location client connection failed");
}

@Override
public void onConnected(Bundle dataBundle) {
    Log.d(TAG, "Location client connected");
    mLocationClient.requestLocationUpdates(mLocationRequest, this); 
}

@Override
public void onDisconnected() {
    Log.d(TAG, "Location client disconnected");
}

@Override
public void onLocationChanged(Location location) {
    if (location != null) {
        Log.d(TAG, "Updated Location: " + Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude()));
    } else {
        Log.d(TAG, "Updated location NULL");
    } 
}     

确保连接/断开LocationClient,以便它仅在绝对必要时使用额外的电池,这样GPS不会无限期运行。LocationClient必须连接才能从中获取数据。

public void onResume() {
    super.onResume();
    mLocationClient.connect();
}

public void onStop() {
    if (mLocationClient.isConnected()) {
        mLocationClient.removeLocationUpdates(this);
    }
    mLocationClient.disconnect();
    super.onStop();
}

获取用户的位置。首先尝试使用LocationClient;如果失败,请返回LocationManager。

public Location getLocation() {
    if (mLocationClient != null && mLocationClient.isConnected()) {
        return mLocationClient.getLastLocation();
    } else {
        LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        if (locationManager != null) {
            Location lastKnownLocationGPS = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if (lastKnownLocationGPS != null) {
                return lastKnownLocationGPS;
            } else {
                return locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
            }
        } else {
            return null;
        }
    }
}

其他回答

通过使用FusedLocationProviderApi,这是最新的API,也是在Android中获取位置的最佳可能性。将其添加到build.gradle文件中

dependencies {
    compile 'com.google.android.gms:play-services:6.5.87'
}

您可以通过此url获取完整的源代码http://javapapers.com/android/android-location-fused-provider/

我已经在demonuts.com上写了详细的教程,介绍了当前位置。您可以在这里找到更多描述,也可以下载整个演示源代码以更好地理解。

这里已经有很多答案,但我想展示使用Google API获取位置的最新方法,这样新程序员就可以使用新方法:

首先,将其放在gradle文件中

compile 'com.google.android.gms:play-services:8.4.0'

然后实现必要的接口

public class MainActivity  extends BaseActivitiy implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener

声明实例

  private GoogleApiClient mGoogleApiClient;
  private Location mLocation;
  private LocationManager locationManager;
  private LocationRequest mLocationRequest;

将其放入onCreate()中

 mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

最后,重写必要的方法

 @Override
    public void onConnected(Bundle bundle) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if(mLocation == null){
            startLocationUpdates();
        }
        if (mLocation != null) {
            double latitude = mLocation.getLatitude();
            double longitude = mLocation.getLongitude();
        } else {
            // Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
        }
    }

    protected void startLocationUpdates() {
        // Create the location request
        mLocationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(UPDATE_INTERVAL)
                .setFastestInterval(FASTEST_INTERVAL);
        // Request location updates
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                mLocationRequest, this);
        Log.d("reque", "--->>>>");
    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.i(TAG, "Connection Suspended");
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
    }

    @Override
    public void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    public void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
    @Override
    public void onLocationChanged(Location location) {

    }

在运行应用程序之前,不要忘记在设备中启动GPS。

我不确定基于位置的服务是否可以从GPS以外的其他基础设施获取位置,但根据那篇文章,这似乎是可能的:

应用程序可以调用几种类型的定位方法。使用移动电话网络:当前单元格ID可用于识别基站收发信机(BTS)设备正在通信以及该BTS的位置。显然,这种方法的准确性取决于单元格的大小,以及可能非常不准确。GSM蜂窝可以是2到20直径千米。另外与细胞ID一起使用的技术可以精度在150米以内。使用卫星:全球定位系统(GPS),受控美国国防部使用由24颗卫星组成的星座围绕地球运行。GPS确定通过计算设备的位置时间差信号来自不同的卫星到达接受者GPS信号是编码的,所以移动设备必须配备使用GPS接收器。GPS是可能是最准确的方法(如果GPS接收机具有清晰的天空视图),但它也有一些缺点:硬件可能很昂贵电池使用时,需要冷启动后的热身对可见卫星的初步定位。它还受到“峡谷效应”的影响在城市,卫星能见度是间歇性的。使用短程定位信标:相对小面积,如单个建筑,局域网可以提供其他位置服务。例如,适当地配备的设备可以使用蓝牙短程定位。

这是我请求用户权限的方式。

在AndroidManifest.xml中的应用程序标记外添加这些权限请求。

<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" />

然后在App Gradle文件中添加Google的位置依赖项。

implementation 'com.google.android.gms:play-services-location:15.0.0'

现在声明一些全局变量。

private lateinit var mFusedLocationProvider:FusedLocationProviderClient
private lateinit var mLocationCallback: LocationCallback
private lateinit var mLocationRequest: LocationRequest
private var mLocationPermissionGranted:Boolean = false

在活动的OnCreate方法中(我无法正确格式化代码,对此深表歉意)

mFusedLocationProvider = LocationServices.getFusedLocationProviderClient(this)

//Location Callback
mLocationCallback = object: LocationCallback(){
 override fun onLocationResult(p0: LocationResult?) {
  if(p0==null){
     //todo(request user to enable location from settings then remove return)
     return
  }else{
      getDeviceLocation()
       }
  }
}

//Location Request
mLocationRequest = LocationRequest.create()
mLocationRequest.priority = LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY
//Set the Interval for Latest Interval Update
mLocationRequest.interval = 5000
//Set How Many Location Updated you Want
mLocationRequest.numUpdates = 1

getLocationPermission()
getDeviceLocation()

现在创建这两个函数。

 private fun getLocationPermission() {

            val permission:Array<String> = arrayOf(android.Manifest.permission.ACCESS_FINE_LOCATION,android.Manifest.permission.ACCESS_COARSE_LOCATION)
            if(ContextCompat.checkSelfPermission(applicationContext,Constant.FINE_LOCATION)== PermissionChecker.PERMISSION_GRANTED){
                if(ContextCompat.checkSelfPermission(applicationContext,Constant.COARSE_LOCATION)== PermissionChecker.PERMISSION_GRANTED){
                    mLocationPermissionGranted = true
                }
            }else{
                ActivityCompat.requestPermissions(this,permission,Constant.LOCATION_REQUEST_CODE)
            }

    }

第二种方法

private fun getDeviceLocation() {
        try{
            if(mLocationPermissionGranted){

                mFusedLocationProvider.lastLocation.addOnCompleteListener(this,{task: Task<Location> ->
                    if(task.isSuccessful){
                        var currentLocation: Location? = task.result
                        if(currentLocation!=null){

                            Log.i("Location","Latitude is ${currentLocation.latitude} and Longitude" +
                                    "${currentLocation.longitude}")
                        }

                        else
                            mFusedLocationProvider.requestLocationUpdates(mLocationRequest,mLocationCallback,null)
                    }
                })
            }
        }catch (e:SecurityException){
            Log.e("Error", "Security Exception ${e.message}")
        }
    }

对于常量.kt

class Constant{
    companion object {

        //Location Request Settings
        const val SET_INTERVAL:Long = 2000
        const val NUM_UPDATES:Int = 1

        //Location Permission
        const val FINE_LOCATION:String = android.Manifest.permission.ACCESS_FINE_LOCATION
        const val COARSE_LOCATION:String = android.Manifest.permission.ACCESS_COARSE_LOCATION
    }
}

建议使用LocationClient:

首先,定义位置更新间隔值。根据您的需要进行调整。

private static final int MILLISECONDS_PER_SECOND = 1000;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;

让您的活动实现GooglePlayServicesClient.ConnectionCallbacks、GooglePlayServicesClient OnConnectionFailedListener和LocationListener。

public class LocationActivity extends Activity implements 
GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {}

然后,在Activity的onCreate()方法中设置LocationClient:

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

    mLocationClient = new LocationClient(this, this, this);

    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequest.setInterval(UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}

将所需方法添加到“活动”中;onConnected()是LocationClient连接时调用的方法。onLocationChanged()是检索最新位置的位置。

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Log.w(TAG, "Location client connection failed");
}

@Override
public void onConnected(Bundle dataBundle) {
    Log.d(TAG, "Location client connected");
    mLocationClient.requestLocationUpdates(mLocationRequest, this); 
}

@Override
public void onDisconnected() {
    Log.d(TAG, "Location client disconnected");
}

@Override
public void onLocationChanged(Location location) {
    if (location != null) {
        Log.d(TAG, "Updated Location: " + Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude()));
    } else {
        Log.d(TAG, "Updated location NULL");
    } 
}     

确保连接/断开LocationClient,以便它仅在绝对必要时使用额外的电池,这样GPS不会无限期运行。LocationClient必须连接才能从中获取数据。

public void onResume() {
    super.onResume();
    mLocationClient.connect();
}

public void onStop() {
    if (mLocationClient.isConnected()) {
        mLocationClient.removeLocationUpdates(this);
    }
    mLocationClient.disconnect();
    super.onStop();
}

获取用户的位置。首先尝试使用LocationClient;如果失败,请返回LocationManager。

public Location getLocation() {
    if (mLocationClient != null && mLocationClient.isConnected()) {
        return mLocationClient.getLastLocation();
    } else {
        LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        if (locationManager != null) {
            Location lastKnownLocationGPS = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if (lastKnownLocationGPS != null) {
                return lastKnownLocationGPS;
            } else {
                return locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
            }
        } else {
            return null;
        }
    }
}