Question

I created a subclass (called MyPicture) of the UIImageView with this methodes:

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.userInteractionEnabled = YES;
    }
    return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    NSLog(@"-- I AM TOUCHED --");
}

//…

When I create a UIImageView with the InterfaceBuilder with the class MyPicture everything works and the console writes: “I AM TOUCHED”. But only, when I activate User Interaction Enabled in IB.

But when I create the UIImageView programmatly, it doenst work.
in the ViewController.h:

MyButton * foo;

In the ViewController.m:

- (void)viewDidLoad {
    flo = [[UIImageView alloc]initWithFrame:CGRectMake(0.0, 45.0, 324, 52.0)];
    foo.userInteractionEnabled = YES;
    foo.image = [UIImage imageNamed:@"Picture 1.png"];
    [self.view addSubview:foo];
    [super viewDidLoad];
}

I can see the picture, so it has to be my UIImageView subclass. But why doesn’t he detect the touches?

Answer 1

I don’t see why it has to be your subclass. Seeing the picture just means it’s a UIImageView. Which is exactly what it is (not the subclass) Here:

foo = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 45.0, 324, 52.0)];

you are initializing a UIImageView, not your sub class. Try changing that line to:

foo = [[MyPicture alloc] initWithFrame:CGRectMake(0.0, 45.0, 324, 52.0)];

Edit: Also, since you set userInteractionEnabled = YES in your subclasses ‘initWithFrame:’ method, there’s no reason you have to do it again in this line:

foo.userInteractionEnabled = YES;