"Programming a Background" – stuck on code challenge

catView is already an instance UIView you don't need to access a view property of it.

Your last line should be:

[catView addSubview:imageView];

It should look like this

[catView.view insertSubview:imageView atIndex:0];

Sorry, but that didn't seem to work. I still get the same error.

Remember that you need to add a subview and not insert a subview.

Thanks, Amit. That worked like a charm. I was getting stuck on the difference between insertSubview and addSubview. I didn't realize the instance negates the need to call the property.

Let me take this time to say that this lesson has been one of the best, most understandable lessons in coding that I've ever received. That counts both face-to-face and online courses. What's especially great is that I'm feeling like I can actually do this, rather than getting really discouraged reading some of the other tutorials.

From one teacher to another, you are doing a great job.

Thank you for the kind words Geoffrey! I really appreciate it.

Stuck here myself - you said that catView was already an instance of UIView - how do we know that?

@Scott the very first line of the Code Challenge defines the catView instance:

    UIView *catView = [[UIView alloc] init];

Could I replace the catView in [catView addSubview:imageView]; with self? So we'd have [self addSubview:imageView]; ?

When I tried it in the code challenge, it didn't work. I can't understand why

Lastly, unrelated to above but is there a way to search the forum?

Thanks!

@yuji self refers to the instance of a particular class. Hence, you see it inside the UIViewController because it is referring to the instance of that particular view controller. In the case of the Code Challenge there is no view controller.

Hi Amit, Could you explain why this is NOT correct:

[self.catView addSubview:imageView];

I'm not fully getting the use of self. (pun not intended :p)

@kurt self refers to the instance of the class within which self is defined. When you say self.catView, you are saying access the property of myself. In the video a view is a property of the view controller hence self.view. In the code challenge catView is simply an instance variable and not a property of some class. The next stage called data modeling in the Blog reader explains this concept very nicely and it should be out next week.

I also had this problem! I started with 'self'. Thanks for explaining... I'm not sure I get it fully, but will read on and hopefully that will compound the theory.

Thanks Amit!

This new stage in the "Build a Blog Reader app" explains self in detail. http://teamtreehouse.com/library/ios-development/build-a-blog-reader-iphone-app/data-modeling

Got stuck here as well. 4 hours of pulling my hair out, I decided to Google for help and landed on this page. I have no idea how I got here....or how to get back to here. Thanks for the answer.