Adding UIButtons to a Cocos2d project - iphone

Question

In Cocos2d, I have read that
[[[[CCDirector sharedDirector] openGLView] window] addSubview:someButton];
will add a UIView to the main window: http://www.cocos2d-iphone.org/forum/topic/3588
Yet in my code I have this:
- (void)onEnterTransitionDidFinish {
UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[[[[CCDirector sharedDirector] openGLView] window] addSubview:button];
}
But no button is visible. This method is part of a CCLayerColor which is the first scene presented in the app, if that matters. What am I doing wrong here? Thanks!
Edit: I can confirm that the buttons are being added to the windows subviews, because NSLogging
[[[[[CCDirector sharedDirector] openGLView] window] subviews] count]
shows a difference when I comment/uncomment the addSubview line. So why isn't the button showing up?
Edit 2:
Thanks to #Marine, I have found that my problem is the way I am declaring my button; using buttonWithType: solved the problem, because this code works:
UIButton* button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setFrame:CGRectMake(100, 100, 100, 100)];
[[[[CCDirector sharedDirector] openGLView] window] addSubview:button];
Can someone explain to me why using this class method works and using initWithFrame: doesn't? Because I would rather not create lots of autoreleased objects, and also because I have some UIButton subclasses that do NOT show up when I use the buttonWithType: method.
Edit 3 (Solution):
The reason why using anything but buttonWithType: doesn't work is that if you do not use that method to create the button, the background color of the button is not set, and by default it is clearColor. Using [button setBackgroundColor:[UIColor redColor]] or any other color fixes the problem. Also, if using a custom button class like this one, you might need to manually call [button awakeFromNib] if the button isn't connected to a nib.

Answer 1

Try the below code it would help you
-(id) init
{
if((self = [super init]))
{
UIView* glView = (UIView*) [[CCDirector sharedDirector] openGLView];
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[btn setFrame:CGRectMake(100, 100, 250, 250)];
[btn addTarget:self action:#selector(actionper:) forControlEvents:UIControlEventTouchUpInside];
[glView addSubview:btn];
}
return self;
}
-(void) actionper : (id) sender
{
printf("\n Stuff of the Code on button Press");
}

Answer 2

I have posted the solution to the problem as an edit to the question.

Answer 3

Try using the bringsubviewtofront method of the OpenGL window passing the recently added button as the argument. Also make sure that the frame of your button is such that it is in the visible part of the screen. Try playing around with it's position.