Question

-(void)viewWillAppear:(BOOL)animated
{
   [super viewWillAppear:animated];
   UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
   imageView.image = [UIImage imageNamed:@"Sample.png"];
   [self.view addSubview:imageView];
   NSArray *subviews = [self.view subviews];
   for(id element in subviews) {
      if ([[element class] isKindOfClass:[UIImageView class]]) //check if the object is a UIImageView
      {
         NSLog(@"element is a UIImageView\n");
         [element setCenter:CGPointMake(500., 500.)];
      } else {
         NSLog(@"element is NOT a UIImageView\n");
      }
   }
}

I expected the output to be “element is a UIImageView, but it’s actually element is NOT a UIImageView. Why? It’s not that there are other subviews. There is only one. Furthermore, when run, the image is displayed at 100,100, not 500,500 as expected.

Answer 1

Your check is wrong. You should call isKindOfClass: on object and not on class of object.

[element isKindOfClass:[UIImageView class]]