Deal with "getSystemService: cannot find symbol"

How-to Discussions
1

Hi everyone,

Here’s my code:

[extern(Android) ForeignInclude(Language.Java,
  "android.location.LocationManager",
  "android.content.Context",
  "android.app.Activity"
    )]
public class Location : NativeModule
{
    // ...

    [Foreign(Language.Java)]
    static extern(Android) bool Test()
    @{
    LocationManager manager = (LocationManager) getSystemService( Context.LOCATION_SERVICE );

    return manager.isProviderEnabled( LocationManager.GPS_PROVIDER );
    @}
}

And then it notifies: “cannot find symbol” at getSystemService method. What should i do? Thanks.

2

Hi David!

The issue here is the getSystemService method belongs to the Activity. The easiest way to get the App’s root activity is to use the com.fuse.Activity.getRootActivity() method.

So your code becomes:

[extern(Android) ForeignInclude(Language.Java,
  "android.location.LocationManager",
  "android.content.Context",
  "android.app.Activity")]
public class Location : NativeModule
{
    // ...

    [Foreign(Language.Java)]
    static extern(Android) bool Test()
    @{
        Activity activity = com.fuse.Activity.getRootActivity();

        LocationManager manager = (LocationManager) activity.getSystemService(Context.LOCATION_SERVICE);

        return manager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    @}
}

You can also get the activity in Uno using the Android.ActivityUtils package (which we really need to document :stuck_out_tongue: )

you add "Android.ActivityUtils" to your unoproj file, and then call

Java.Object activity = Android.ActivityUtils.GetRootActivity();

You can also launch activities from there, see here: https://gist.github.com/cbaggers/489e2533570f246e32157e0018cab95c for an example

I hope this helps

3

It works. Thanks Chris.

4

Anytime! thanks for posting your result.