为什么我的 GPS 坐标显示为零？

Question

我正在制作这个简单的应用程序，当放置按钮时，应该显示用户 gps 位置，并且它在模拟器上运行良好，但是当我在真实手机中尝试时，经度和纬度都为零。

这是我的代码： 主要活动：

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final TextView longS = (TextView) findViewById(R.id.longi);
        final TextView latiS = (TextView) findViewById(R.id.lati);

        Button btn_show_location = (Button) findViewById(R.id.button1);

        btn_show_location.setOnClickListener(new View.OnClickListener() {  
             public void onClick(View view) {  
                 LocationManager mlocManager=null;  
                 LocationListener mlocListener;  
                 mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);  
                 mlocListener = new MyLocationListener();  
                mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);  

                if (mlocManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {  
                    if(MyLocationListener.latitude>0)  
                    {  
                         longS.setText("Latitude:- " + MyLocationListener.latitude);  
                         latiS.setText("Longitude:- " + MyLocationListener.longitude + '\n');  
                     }  
                     else  
                     {  
                          longS.setText("Please wait");
                      }  
                  } else {  
                      Intent gpsOptionsIntent = new Intent(  
                                android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);  
                            startActivity(gpsOptionsIntent); 
                  }  

              }  
         });  
    }

我的位置监听器：

public class MyLocationListener implements LocationListener {  

    public static double latitude;  
    public static double longitude;  

    @Override  
    public void onLocationChanged(Location loc)  
    {  
       // loc.getLatitude();  
        //loc.getLongitude();  
        latitude=loc.getLatitude();  
        longitude=loc.getLongitude();  
    }  

    @Override  
    public void onProviderDisabled(String provider)  
    {  
        //print "Currently GPS is Disabled";  
    }  
    @Override  
    public void onProviderEnabled(String provider)  
    {  
        //print "GPS got Enabled";  
    }  
    @Override  
    public void onStatusChanged(String provider, int status, Bundle extras)  
    {  
    }  
}  

清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.databasecollect"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="21" />

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>  
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".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>

Answer 1

这是适合我的 GPS 追踪器课程。 （另见这些链接）：

http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/

GPS Location not being changed android

http://niravranpara.blogspot.com/2013/04/android-get-current-gps-location.html

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 = 0; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0; // 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) {
        Log.d("GPS Tracking Exception", e.toString());
        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 launch 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) {
    //this.location = getLocation();
    this.location = location;
    //getLocation();
    // Testing onLocationChanged:
    String hej1 = Double.toString(location.getLatitude());
    String hej2 = Double.toString(location.getLongitude());
    //Toast.makeText(getApplicationContext(), "Location: "+"Lat: " + hej1 + "Long: " + hej2,Toast.LENGTH_LONG).show();
}

@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;
}

}