Question

I’m trying to use code such as the following Objective-C in MonoTouch:

if (NSClassFromString(@"ADBannerView"))

What is the equivalent in C#?

Basically I’m wanting to use iAd, but I need to check for the existance of ADBannerView and ADInterstitialAd, because they are not available on all versions of the OS. (And I’d rather do feature checking than iOS version checking)

I think this could be helpful in other situations as well.

Answer 1

A recent MonoTouch will always provide ADBannerView so you cannot the the C# equivalent of Type.GetType to query availability.

Normally a version check is the best way to check for features. E.g.

bool available = UIDevice.CurrentDevice.CheckSystemVersion (4, 0);

will return true for any 4.0+ versions of iOS (4.0 being when ADBannerView was added to iOS).

A possible alternative (might not work in every case) is to create an instance and check it’s handle. Since ObjC is message based sending init will return null (something a .NET constructor can’t do). E.g.

bool available = (new ADBannerView ().Handle != IntPtr.Zero);

Note that you probably best surround the above with using to dispose the view or integrate this inside the normal creation of your ADBannerView.

UPDATE: of course a p/invoke to NSClassFromString would do exactly the same as the ObjectiveC code 🙂