Question

Does anybody know why I get the following error message when I try to build the default “MonoGame.Framework.iOS.sln” on Monotouch? And how I can fix this? :

on line 468 of the Guide source file (From MonoGame.Framework.iOS>iOS>GamerServices>Guide.cs
I get,

public static void ShowMatchMaker()
{
     AssertInitialised ();

if ( ( Gamer.SignedInGamers.Count > 0 ) && ( Gamer.SignedInGamers[0].IsSignedInToLive ) )
   {
    // Lazy load it
if ( matchmakerViewController == null )
   {
     matchmakerViewController = new GKMatchmakerViewController(); }

// error on that line is– type ‘MonoTouch.GameKit.GKMatchmakerViewController’ does not contain a constructor that takes ‘0’ arguments.

Answer 1

The default constructor (actually the init selector for the GKMatchmakerViewController type) was invalid (sadly Apple documentation on what can be initialized with init is a bit lacking).

Also starting with iOS6 this would throws an ObjectiveC exception at runtime:

Objective-C exception thrown.  
Name: NSInvalidArgumentException 
Reason: <GKMatchmakerViewController: 0x16101160>: 
must use one of the designated initializers

As such this default constructor, along with a few others, were removed since their use could cause weird crashes in earlier iOS releases (and you do not want your game to misbehave on iOS6 anyway).