Disposing of a NSTimer correctly in Monotouch - iphone

Question

In my app, I need a one off timer that'll perform an action and never be used again. I've been cracking down on performance lately and was wondering what the correct way to do this would be.
If I do the following:
NSTimer.CreateScheduledTimer(10, delegate {
Console.WriteLine("Timer fired!");
// other non-trivial code here
});
Once this has fired, is this going to be automagically cleaned up by Mono's GC? Or would it be better to create a reference to this timer (NSTimer timer = NSTimer.CreateScheduledTimer()) and then dispose of it myself?
Does this apply to other objects which can be instantiated in a similar manner?

Answer 1

Your sample code is probably the way to go. GC will clean up sometime after the timer has fired. The only reason you might want to hold a reference to the timer is if you'd want to cancel the timer at some point.

Answer 2

I use this little helper. Good thing is that it can be used in all NSObject derived classes and helps when converting code from ObjC as it is pretty much the same call.
namespace MonoTouch.Foundation.Extensions
{
public static class CoreFoundationExtensions
{
/// <summary>
/// Performs the selector.
/// </summary>
/// <param name='obj'>
/// Object.
/// </param>
/// <param name='action'>
/// Action.
/// </param>
/// <param name='delay'>
/// Delay.
/// </param>
public static void PerformSelector (this NSObject obj, NSAction action, float delay)
{
int d = (int)(1000 * delay);
var thread = new Thread(new ThreadStart ( () => {
using(var pool = new NSAutoreleasePool())
{
Thread.Sleep (d);
action.Invoke ();
}
}));
thread.IsBackground = true;
thread.Start();
}
/// <summary>
/// Performs the selector.
/// </summary>
/// <param name='obj'>
/// Object.
/// </param>
/// <param name='action'>
/// Action.
/// </param>
public static void PerformSelector (this NSObject obj, NSAction action)
{
PerformSelector (obj, action, 0.001f);
}
}
}