如何在Android中获取当前位置
我有使用Android位置系统的NETWORK提供程序获取我当前的位置坐标的麻烦。
已经阅读了大量的教程，并实施了4或5个现有的类到我的项目，他们都给我最后的坐标，但不是现有的。
我很确定，这个问题是我失踪的根本原因，但我无法理解它究竟是什么。
现在使用的代码：
这是我的主要活动
package com.example.locationtests; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.widget.TextView; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); GPSTracker mGPS = new GPSTracker(this); TextView text = (TextView) findViewById(R.id.texts); if(mGPS.canGetLocation ){ mGPS.getLocation(); text.setText("Lat"+mGPS.getLatitude()+"Lon"+mGPS.getLongitude()); }else{ text.setText("Unabletofind"); System.out.println("Unable"); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } } 这是我用于跟踪的课程：
package com.example.locationtests; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.provider.Settings; import android.util.Log; public final class GPSTracker implements LocationListener { private final Context mContext; // flag for GPS status public 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 = 1; // 10 meters // The minimum time between updates in milliseconds private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute // Declaring a Location Manager protected LocationManager locationManager; public GPSTracker(Context context) { this.mContext = context; getLocation(); } /** * Function to get the user's current location * * @return */ public Location getLocation() { try { locationManager = (LocationManager) mContext .getSystemService(Context.LOCATION_SERVICE); // getting GPS status isGPSEnabled = locationManager .isProviderEnabled(LocationManager.GPS_PROVIDER); Log.v("isGPSEnabled", "=" + isGPSEnabled); // getting network status isNetworkEnabled = locationManager .isProviderEnabled(LocationManager.NETWORK_PROVIDER); Log.v("isNetworkEnabled", "=" + isNetworkEnabled); if (isGPSEnabled == false && isNetworkEnabled == false) { // no network provider is enabled } else { this.canGetLocation = true; if (isNetworkEnabled) { location=null; 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) { location=null; 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) { } }
这是我的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.locationtests" android:versionCode="1" android:versionName="1.0" > <uses-permission android:name="android.permission.CAMERA" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.INTERNET"></uses-permission> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android.permission.VIBRATE" /> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.location" android:required="true" /> <uses-feature android:name="android.hardware.location.gps" android:required="false" /> <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.locationtests.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
Acctualy GPS定位工作正常，但networking定位dosn't。 当Ive开启设备时，坐标系上的GPS在不断移动的同时不断变化，但是当我将其closures并继续使用NETWORK_PROVIDER
首先，您需要定义一个LocationListener来处理位置更改。
private final LocationListener mLocationListener = new LocationListener() { @Override public void onLocationChanged(final Location location) { //your code here } };
然后获取LocationManager并请求位置更新
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE); mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, LOCATION_REFRESH_TIME, LOCATION_REFRESH_DISTANCE, mLocationListener); }
最后确保你已经在Manifest上添加了许可，
只使用基于networking的位置使用这一个
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
对于基于GPS的位置，这一个
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
您需要在OnLocationChanged方法中编写代码，因为在位置发生更改时会调用此方法 。 即你需要保存新的位置来返回它，如果调用getLocation。
如果你不使用onLocationChanged，它将永远是旧的位置。
我正在使用这个教程 ，它适用于我的应用程序。
在我的活动中，我把这个代码：
GPSTracker tracker = new GPSTracker(this); if (!tracker.canGetLocation()) { tracker.showSettingsAlert(); } else { latitude = tracker.getLatitude(); longitude = tracker.getLongitude(); }
还要检查您的模拟器是否使用Google API运行
