永远不会调用iOS6 authenticateHandler

Question

我有以下代码来验证GameKit中的本地用户。没有诊断也没有崩溃，但从不使用处理程序，并且从不对本地用户进行身份验证。有人可以说为什么？这种身份验证方式遵循Cocos2d上的Wenderlich博客。 ANNOUNCE和CCLOG行是我的调试方法，它们显示调用该方法但不调用处理程序。冗余外观的BOOL也来自调试。我在iOS6 iPhone上测试。此代码位于AppDelegate中。

-(void) authenticateLocalPlayer {
    ANNOUNCE
    GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
    localPlayer.authenticateHandler = ^(UIViewController *viewController, NSError *error) {
        [self setLastError:error];
        if ( [CCDirector sharedDirector].isPaused ) [[CCDirector sharedDirector] resume];
        CCLOG(@"inside authenticateHandler");
        if (localPlayer.authenticated) {
            _gameCenterFeaturesEnabled = YES;
            X.localPlayerAuthenticated = YES;
        } else if (viewController) {
            [[CCDirector sharedDirector] pause];
            [self presentViewController:viewController];
        } else {
            _gameCenterFeaturesEnabled = NO;
            X.localPlayerAuthenticated = NO;
        }
    };
    CCLOG(@"lastError: %@", self.lastError);
    CCLOG(@"localPlayer.authenticated: %d", localPlayer.authenticated);
}