GPS定位器不工作

Question

我正在尝试通过GPS获取当前用户位置。我已经阅读了关于这方面的谷歌文档，并尝试了一些教程，但似乎没有什么能正常工作。这是我的代码：

public class useGPS extends Activity implements LocationListener
{
private static final String TAG = "useGPS:";
LocationManager myLocManager;
TextView locationData;
@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate( savedInstanceState );
    setContentView( R.layout.use_gps );
    myLocManager = ( LocationManager )this.getSystemService( LOCATION_SERVICE );
    Location location = myLocManager.getLastKnownLocation( myLocManager.GPS_PROVIDER) ;
    if( location != null )
    {
        Log.d( TAG,location.toString() );
        Toast.makeText( this, "Location changed...", Toast.LENGTH_SHORT);
        this.onLocationChanged( location );
    }
}
@Override
protected void onResume() 
{
    super.onResume();
    myLocManager.requestLocationUpdates( myLocManager.GPS_PROVIDER, 3000, 0, this );
}
@Override
protected void onPause()
{
    super.onPause();
    myLocManager.removeUpdates( this );
}

@Override
public void onLocationChanged(Location location) 
{
    Log.d( TAG,"onLocationChanged with location: "+location.toString() );
    // Return a string representation of the latitude & longitude. Pass it to the textview and update the text
    String text = "Lat: "+location.getLatitude()+"nLong: "+location.getLongitude();
    locationData = (TextView)findViewById( R.id.locationData );
    locationData.setText( text );
}
@Override
public void onProviderDisabled(String provider) {
    Toast.makeText( getApplicationContext(), "Provider Disabled...", Toast.LENGTH_SHORT );
}
@Override
public void onProviderEnabled(String provider) 
    {
    Toast.makeText( getApplicationContext(), "Provider Enabled...", Toast.LENGTH_SHORT );
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub
}

我知道GPS在室内往往不起作用，所以我在室外站了5分钟，但没有什么不同。当我使用模拟器模拟一个位置时，它返回了lat&长的位置很好-没有错误。

此外，我在清单文件中包含了必要的权限，如下所示：

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

你知道为什么这不起作用吗？

Answer 1

好的，所以我解决了这个问题——我决定调整代码来创建监听器，而不是在类中实现它。我还确保在requestLocationUpdates上调用了NETWORK_PROVIDER和GPS_PROVIDER，以覆盖这两个基础。这是修改后的代码，请注意，注释掉的地理编码部分暂时会导致程序崩溃，我还没有解决错误。。。

public class useGPS extends Activity
{
private static final String TAG = "useGPS:";
TextView locationData, addressData;
LocationManager myLocManager;
LocationListener locationListener;
@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate( savedInstanceState );
    setContentView( R.layout.use_gps );
    // Acquire a reference to the system Location Manager
    myLocManager = (LocationManager) this.getSystemService( Context.LOCATION_SERVICE );
    // Define a listener that responds to location updates
    locationListener = new LocationListener()
    {
        @Override
        public void onLocationChanged(Location location) 
        {
            // Return a string representation of the latitude & longitude. Pass it to the textview and update the text
            String text = "Lat: "+location.getLatitude()+"nLong: "+location.getLongitude();
            locationData = (TextView)findViewById( R.id.locationData );
            locationData.setText( text );
            /**
            try
            {
                // Reverse Geocoding
                Geocoder geocoder = new Geocoder( getApplicationContext(), Locale.getDefault() );
                List<Address> addresses = geocoder.getFromLocation( location.getLatitude(), location.getLongitude(),0 );
                if( addresses != null )
                {
                    // Get return address data
                    Address returnedAddress = addresses.get( 0 );
                    StringBuilder strReturnedAddress = new StringBuilder( "Address:n" );
                    for( int i = 0; i < returnedAddress.getMaxAddressLineIndex(); i++ )
                    {
                        // Return the address
                        strReturnedAddress.append( returnedAddress.getAddressLine(i) ).append( "n" );
                    }
                    // Set our textview to the address returned
                    addressData.setText( strReturnedAddress.toString() );
                } else {
                    addressData.setText( "Sorry, no address returned..." );
                }
            } catch( IOException e )
            {
                // Catch the Exception
                e.printStackTrace();
                addressData.setText( "Error: Cannot get Address!" );
            }
            */
        }
        @Override
        public void onProviderDisabled(String provider) 
        {
        }
        @Override
        public void onProviderEnabled(String provider) 
        {
        }
        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) 
        {
        }
    };
    // The two lines below request location updates from both GPS & the network location provider
    myLocManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 0, 0,locationListener );
    myLocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0,locationListener );
}
@Override
protected void onResume() 
{
    super.onResume();
    // The two lines below request location updates from both GPS & the network location provider
    myLocManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 0, 0,locationListener );
    myLocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0,locationListener );
}
@Override
protected void onPause()
{
    super.onPause();
    // The two lines below request location updates from both GPS & the network location provider
    myLocManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 0, 0,locationListener );
    myLocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0,locationListener );
}
}

最后一点-到目前为止，我不确定是否需要onResume（）和onPause（）方法上的两个requestLocationUpdate方法。onResume（）方法可能会被更改为获取最后一个已知位置（如果有），而不是重新建立位置更新方法。

希望这能帮助其他人。。。