Toggle airplane mode monotouch xamarin

Question

Note: this isn't an app for the App Store, so using private API's isn't a concern to me.

I've been trying to toggle Airplane mode off and back on using Xamarin/Monotouch based off this SO question: How to turn on/off airplane mode in IOS 5.1 using private API

I'm having a hard time getting this code to run in monotouch - first thing I tried was to create a native objective C library using a monotouch binding project.

The AppSupport framework is used so my linkwith file is as follows:

[assembly: LinkWith ("libAirplaneModeLib.a", LinkTarget.ArmV7, ForceLoad = true, Frameworks = "AppSupport")]

When I do this, it compiles but I can't reference the namespace from my main project. If I don't include the framework as follows:

[assembly: LinkWith ("libAirplaneModeLib.a", LinkTarget.ArmV7, ForceLoad = true)]

In this case I can reference the namespace, but the main project compiles on linking with:

  "_OBJC_CLASS_$_RadiosPreferences", referenced from:
      objc-class-ref in libAirplaneModeLib.a(AirplaneModeLib.o)
ld: symbol(s) not found for architecture armv7
collect2: ld returned 1 exit status

error MT5202: Native linking failed. Please review the build log.

My ApiDefinition file is as follows:

[BaseType(typeof(NSObject))]
public interface AirplaneModeLib
{
    [Export("toggleAirplane")]
    void ToggleAirplane ();
}

The native library is as follows:

#import "AirplaneModeLib.h"
#import "RadiosPreferences.h"

@implementation AirplaneModeLib

- (void) toggleAirplane {
    RadiosPreferences* preferences = [[RadiosPreferences alloc] init];
    preferences.airplaneMode = NO;
    [preferences synchronize];

    preferences.airplaneMode = YES; 
    [preferences synchronize];
    [preferences release];        
}

@end

Is there a better or easier way to do this? If not, can anyone suggest what I'm doing wrong with my current approach?

Answer 1

It seems I've solved it. For some reason the binding project can't reference the AppSupport framework (or can, by some method I'm not aware of)

In my main project I manually added the additional build arguments

-gcc_flags "-F /path/to/framework -framework AppSupport"

And it compiles fine now. Still doesn't toggle airplane mode, but that's a separate issue I guess...

It appears that even though this code will run, it will not toggle airplane mode. As far as I can tell there is no way to do this with a non-jailbroken device in iOS 5+.