Question

Here is the code:

CGRect myImageRect = CGRectMake(0, 0, 100, 100);
UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:@"Angry0.png"]];
[mainView addSubview:myImage];

Angry0.png is in my Resources folder. No image is display on simulator.

Answer 1

Right… You need to initalize all your views…

If I’m right your view hierarchy is this:

-mainView
     -contentView
         -scrollView
              -imageView

So somewhere when you load mainView you also need to initalize all the child views…

For example:

...
//put this where you call mainView = [[UIView alloc] init...

contentView = [[UIView alloc] init...
//config the contentView

scrollView = [[UIScrollView alloc] init...
//config the scrollView

....

Now, providing that you correctly set your views frames and initialized them they shouldn’t be null…

You can check by calling:

if (!scrollView) {
    NSLog(@"scrollView is null :(");
}

Then you should be able to call your existing code and all should be good