GPS程序适用于JellyBean和KitKat，但不适用于Gingerbread

Question

I am have written an app to find the GPS coordinates. The program works totally fine on Android 4.3 and 4.4.2 but for some reason its not working on 2.3.4 and 2.3.6. The GPS is not even turning on. Is there something additional that needs to be done to make it compatible with older APIs? I have included the following permissions in the manifest:

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

This is the code :

package com.hari.gps;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
public static Context mContext;

public static Context getContext() {
    return mContext;
}

public void setContext(Context mContext) {
    MainActivity.mContext = mContext;
}
private LocationManager locationManager;
private String provider;
public static float lat, lng;
public static TextView t3, t4, t5, t6;
// SMSReceiver s;
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    latituteField = (TextView) findViewById(R.id.text1);
    longitudeField = (TextView) findViewById(R.id.text2);
    // Get the location manager
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    // Define the criteria how to select the locatioin provider -> use
    // default
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    Location location = locationManager.getLastKnownLocation(provider);

    // Initialize the location fields
    if (location != null) {
        System.out.println("Provider " + provider + " has been selected.");
        onLocationChanged(location);
    } else {
        latituteField.setText("Location not available");
        longitudeField.setText("Location not available");
    }

}

/* Request updates at startup */
@Override
protected void onResume() {
    super.onResume();
    // s.onReceive(getApplicationContext(), getIntent());
    //
    // t3.setText(s.messageReceived);
    locationManager.requestLocationUpdates(provider, 400, 1, this);
}

public void msg(View view) {
    EditText e1 = (EditText) findViewById(R.id.edit);
    String phoneno = "8056371433";
    String s = e1.getText().toString();
    String message, m1, m2;
    t3 = (TextView) findViewById(R.id.text3);
    t4 = (TextView) findViewById(R.id.text4);
    t5 = (TextView) findViewById(R.id.text5);
    t6 = (TextView) findViewById(R.id.text6);
    m1 = String.valueOf(lat);
    m2 = String.valueOf(lng);
    message = m1 + " " + m2;
    if (e1.getText().length() == 0)
        sendSMS(phoneno, message);
    else
        sendSMS(s, message);
}

private void sendSMS(String phoneNumber, String message) {
    String SENT = "SMS_SENT";
    String DELIVERED = "SMS_DELIVERED";

    PendingIntent sentPI = PendingIntent.getBroadcast(MainActivity.this, 0,
            new Intent(SENT), 0);

    PendingIntent deliveredPI = PendingIntent.getBroadcast(
            MainActivity.this, 0, new Intent(DELIVERED), 0);
    SmsManager sms = SmsManager.getDefault();
    sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI);
}

/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {
    boolean flag1 = true, flag2 = true;
    lat = (float) (location.getLatitude());
    lng = (float) (location.getLongitude());
    if (lng < 0) {
        lng = -lng;
        flag1 = false;
    }
    if (lat < 0) {
        lat = -lat;
        flag2 = false;
    }

    if (flag2)
        latituteField.setText("Latitude = " + lat + " N" + "\n");
    else
        latituteField.setText("Latitude = " + lat + " S" + "\n");

    if (flag1)
        longitudeField.setText("Longitude = " + lng + " E");
    else
        longitudeField.setText("Longitude = " + lng + " W");
    // deg = Math.abs((int) lat);
    // min = (int) ((lat - (float) deg) * 60.0);
    // sec = (int) ((((lat - (float) deg) * 60) - min) * 60);
    // if (flag2)
    // latituteField.setText("Latitude    =  " +String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'N'+"\n");
    // else
    // latituteField.setText("Latitude    =  " +String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'S'+"\n");
    // deg = Math.abs((int) lng);
    // min = (int) ((lng - (float) deg) * 60.0);
    // sec = (int) ((((lng - (float) deg) * 60) - min) * 60);
    // if (flag1)
    // longitudeField.setText("Longitude = " + String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'E');
    // else
    // longitudeField.setText("Longitude = " + String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'W');
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String provider) {
    Toast.makeText(this, "Enabled new provider " + provider,
            Toast.LENGTH_SHORT).show();

}

@Override
public void onProviderDisabled(String provider) {
    Toast.makeText(this, "Disabled provider " + provider,
            Toast.LENGTH_SHORT).show();
}

}

Answer 1

I had to add requestlocationupdates() to make it work Strange that I was getting GPS coordinates without using the said function on Jellybean and KitKat. So the modified code is :

Criteria criteria = new Criteria();
Location location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
provider = locationManager.getBestProvider(criteria, true);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

Answer 2

//start public class MainActivity extends FragmentActivity implements GooglePlayServicesClient.ConnectionCallbacks,GooglePlayServicesClient.OnConnectionFailedListener,com.google.android.gms.location.LocationListener,com.google.android.gms.maps.GoogleMap.OnMapClickListener,OnMapLongClickListener,OnMarkerClickListener,GoogleMap.OnInfoWindowClickListener { // Update interval in milliseconds for location services private static final long UPDATE_INTERVAL = 5000; // Fastest update interval in milliseconds for location services private static final long FASTEST_INTERVAL = 1000; // Google Play diagnostics constant private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000; // Speed threshold for orienting map in direction of motion (m/s) private static final double SPEED_THRESH = 1; private static final String TAG = "Mapper"; private LocationClient locationClient; private Location currentLocation; private double currentLat; private double currentLon; private GoogleMap map; private LatLng map_center; private int zoomOffset = 5; private float currentZoom; private float bearing; private float speed; private float acc; private Circle localCircle; private double lon; private double lat; static final int numberOptions = 10; String [] optionArray = new String[numberOptions]; // Define an object that holds accuracy and frequency parameters LocationRequest locationRequest; // Set up shared preferences to persist data. We will use it later // to save the current zoom level if user leaves this activity, and // restore it when she returns. SharedPreferences prefs; SharedPreferences.Editor prefsEditor; @SuppressLint("NewApi") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Get a handle to the Map Fragment // map = ((MapFragment) getFragmentManager() // .findFragmentById(R.id.mapme_map)).getMap(); map=((SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.mapme_map)).getMap(); if(map != null){ // Set the initial zoom level of the map currentZoom = map.getMaxZoomLevel()-zoomOffset; // Add a click listener to the map map.setOnMapClickListener(this); // Add a long-press listener to the map map.setOnMapLongClickListener(this); // Add Marker click listener to the map map.setOnMarkerClickListener(this); // Add marker info window click listener map.setOnInfoWindowClickListener(this); } else { Toast.makeText(this, "error", Toast.LENGTH_LONG).show(); } /* Create new location client. The first 'this' in args is the present * context; the next two 'this' args indicate that this class will handle * callbacks associated with connection and connection errors, respectively * (see the onConnected, onDisconnected, and onConnectionError callbacks below). * You cannot use the location client until the onConnected callback * fires, indicating a valid connection. At that point you can access location * services such as present position and location updates. */ locationClient = new LocationClient(this, this, this); // Create the LocationRequest object locationRequest = LocationRequest.create(); // Set request for high accuracy locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); // Set update interval locationRequest.setInterval(UPDATE_INTERVAL); // Set fastest update interval that we can accept locationRequest.setFastestInterval(FASTEST_INTERVAL); // Get a shared preferences prefs = getSharedPreferences("SharedPreferences", Context.MODE_PRIVATE); // Get a SharedPreferences editor prefsEditor = prefs.edit(); // Keep screen on while this map location tracking activity is running getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); } // Following two methods display and handle the top bar options menu for maps // Save the current zoom level when going into the background @Override protected void onPause() { // Store the current map zoom level if(map != null){ currentZoom = map.getCameraPosition().zoom; prefsEditor.putFloat("KEY_ZOOM",currentZoom); prefsEditor.commit(); } super.onPause(); Log.i(TAG,"onPause: Zoom="+currentZoom); } @Override protected void onResume() { super.onResume(); // Restore previous zoom level (default to max zoom level if // no prefs stored) if (prefs.contains("KEY_ZOOM") && map != null){ currentZoom = prefs.getFloat("KEY_ZOOM", map.getMaxZoomLevel()); } Log.i(TAG,"onResume: Zoom="+currentZoom); // Keep screen on while this map location tracking activity is running getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); } /* The following two lifecycle methods conserve resources by ensuring that * location services are connected when the map is visible and disconnected when * it is not. */ // Called by system when Activity becomes visible, so connect location client. @Override protected void onStart() { super.onStart(); locationClient.connect(); } // Called by system when Activity is no longer visible, so disconnect location // client, which invalidates it. @Override protected void onStop() { // If the client is connected, remove location updates and disconnect if (locationClient.isConnected()) { locationClient.removeLocationUpdates(this); } locationClient.disconnect(); // Turn off the screen-always-on request getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); super.onStop(); } }