Android应用程序中的GPS_PROVIDER错误

Question

I have created an Android app to retrieve the location. I tried to use GPS_PROVIDER, it returned null.. But works smooth when i use NETWORK_PROVIDER.. Can any one help me fixing this?

Here is the code

Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

The location turns null when i replace "NETWORK_PROVIDER" by "GPS_PROVIDER" ..

I have added the following three permissions in manifest

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

Answer 1

There can be two reasons why your GPS location is null

1. May be your GPS is not active. Try to active your GPS from the setting menu => Location & Security => Check Use GPS Satellites .
2. May be you are currently in the building where the GPS is not working. Check it by coming out from the building. This can be happen most of time.

Answer 2

As per documentation

If the provider is currently disabled, null is returned.

Ensure your GPS is active on the device so you don't receive null.

Edit:
Also try running requestLocationUpdates() with GPS_PROVIDER or maybe twice, with NETWORK_PROVIDER as well. The LocationManager retrieves the location the fastest way and it stops searching. Since GPS location is retrieved slower than the network location, is stops right after if finds it therefore returning null for the GPS.

Answer 3

The location turns null when i replace "NETWORK_PROVIDER" by "GPS_PROVIDER"

To solve this issue be sure to have enabled the Location services :

remember the docs:

If the provider is currently disabled, null is returned.

As an option you can use both providers if GPS is disabled then check network provider:

...
 myLocation = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
 if(myLocation == null) {
            myLocation = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
 }

    if(myLocation != null) {
         //Get values for latitude and longitude!
    }
...