42.Android LocationManager

42.Android LocationManager

Android LocationManager
LocationManager 介绍

LocationManager 获取

LocationListener 初始化

LocationManager 添加监听

LocationManager 取得所有Provider

LocationManager 匹配合适Provider

LocationManager 测试代码

LocationManager 介绍

LocationManager 提供了访问系统位置服务，这些服务允许应用程序能够获得定期更新设备的地理位置。

由于 LocationManager 属于一种系统服务类型，所以还是需要通过：

Context.getSystemService(Context.LOCATION_SERVICE)

于此同时，还要在AndroidManifest.xml里配置如下权限：

精确位置权限

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

粗糙位置权限

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

LocationManager 获取

LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

LocationListener 初始化

LocationListener locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
/**
* 经度
* 纬度
* 海拔
*/
Log.i(TAG, "Longitude:" + Double.toString(location.getLongitude()));
Log.i(TAG, "Latitude:" + Double.toString(location.getLatitude()));
Log.i(TAG, "getAltitude:" + Double.toString(location.getAltitude()));
}

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

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
};

LocationManager 添加监听

在LocationManager的源码中有这段：

/**
* Name of the network location provider.
* <p>This provider determines location based on
* availability of cell tower and WiFi access points. Results are retrieved
* by means of a network lookup.
*/
public static final String NETWORK_PROVIDER = "network";

/**
* Name of the GPS location provider.
*
* <p>This provider determines location using
* satellites. Depending on conditions, this provider may take a while to return
* a location fix. Requires the permission
* {@link android.Manifest.permission#ACCESS_FINE_LOCATION}.
*
* <p> The extras Bundle for the GPS location provider can contain the
* following key/value pairs:
* <ul>
* <li> satellites - the number of satellites used to derive the fix
* </ul>
*/
public static final String GPS_PROVIDER = "gps";

/**
* A special location provider for receiving locations without actually initiating
* a location fix.
*
* <p>This provider can be used to passively receive location updates
* when other applications or services request them without actually requesting
* the locations yourself.  This provider will return locations generated by other
* providers.  You can query the {@link Location#getProvider()} method to determine
* the origin of the location update. Requires the permission
* {@link android.Manifest.permission#ACCESS_FINE_LOCATION}, although if the GPS is
* not enabled this provider might only return coarse fixes.
*/
public static final String PASSIVE_PROVIDER = "passive";

有这三种Provider：

NETWORK_PROVIDER

GPS_PROVIDER

PASSIVE_PROVIDER

LocationManager.requestLocationUpdates

public void requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener)

provider：LocationManager的类型（上述的三种填写一个）

minTime：两次定位的最小时间间隔（最少多少秒更新一次）

minDistance：两次定位的最小距离（最少走多远就更新一次）

listener：LocationListener 实例

this.locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, locationListener);

LocationManager 取得所有Provider

LocationManager.getAllProviders

public List<String> getAllProviders()

LocationManager 匹配合适Provider

这里要用到一个类 - Criteria。

/**
* 获取以下条件下，最合适的provider
*/
private void getBestProvider() {
Criteria criteria = new Criteria();
// 精度高
criteria.setAccuracy(Criteria.ACCURACY_FINE);
// 低消耗
criteria.setPowerRequirement(Criteria.POWER_LOW);
// 海拔
criteria.setAltitudeRequired(true);
// 速度
criteria.setSpeedRequired(true);
// 费用
criteria.setCostAllowed(false);
String provider = locationManager.getBestProvider(criteria, false); //false是指不管当前适配器是否可用
this.bestProviderTV.setText(provider);
}

LocationManager 测试代码

LocationManagerActivity

public class LocationManagerActivity extends AppCompatActivity {

private static final String TAG = "LocationManagerActivity";

private LocationManager locationManager;

private TextView longitudeTV;
private TextView latitudeTV;
private TextView altitudeTV;
private TextView providersTV;
private TextView bestProviderTV;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.activity_location_manager);
this.initViews();
this.locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
/**
* 经度
* 纬度
* 海拔
*/
Log.i(TAG, "Longitude:" + Double.toString(location.getLongitude()));
Log.i(TAG, "Latitude:" + Double.toString(location.getLatitude()));
Log.i(TAG, "getAltitude:" + Double.toString(location.getAltitude()));
}

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

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
};
this.locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, locationListener);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
this.longitudeTV.setText(location.getLongitude() + "");
this.latitudeTV.setText(location.getLatitude() + "");
this.altitudeTV.setText(location.getAltitude() + "");

this.getProviders();
this.getBestProvider();
}

/**
* 获取全部的provider
*/
private void getProviders() {
String providers = "";
for (String provider : this.locationManager.getAllProviders()) {
providers += provider + " ";
}
this.providersTV.setText(providers);
}

/**
* 获取以下条件下，最合适的provider
*/
private void getBestProvider() {
Criteria criteria = new Criteria();
// 精度高
criteria.setAccuracy(Criteria.ACCURACY_FINE);
// 低消耗
criteria.setPowerRequirement(Criteria.POWER_LOW);
// 海拔
criteria.setAltitudeRequired(true);
// 速度
criteria.setSpeedRequired(true);
// 费用
criteria.setCostAllowed(false);
String provider = locationManager.getBestProvider(criteria, false); //false是指不管当前适配器是否可用
this.bestProviderTV.setText(provider);
}

private void initViews() {
this.longitudeTV = (TextView) this.findViewById(R.id.location_longitude_tv);
this.latitudeTV = (TextView) this.findViewById(R.id.location_latitude_tv);
this.altitudeTV = (TextView) this.findViewById(R.id.location_altitude_tv);
this.providersTV = (TextView) this.findViewById(R.id.location_providers_tv);
this.bestProviderTV = (TextView) this.findViewById(R.id.location_best_provider_tv);
}

}