Question

I’m having a problem with labels. I have a couple of labels that I need to change with help of tags. I do this in my code, but it gives an exception
-[UIView setText:]: unrecognized selector sent to instance
This is my code:

UILabel *label = (UILabel *)[self.view viewWithTag:0];

label.text = @"empty";

Any help appreciated, thanks.

Answer 1

Every view’s tag is default to 0.

tag

An integer that you can use to identify view objects in your
application.

@property(nonatomic) NSInteger tag

Discussion

The default value is 0.
You can set the value of this tag and use that value to identify the
view later.

Your viewWithTag will return your self.view. So you will get a UIView instead of a UILabel and your app will crash. See viewWithTag‘s definition:

viewWithTag:

Returns the view whose tag matches the specified value.

- (UIView *)viewWithTag:(NSInteger)tag
Parameters

tag

The tag value to search for. Return Value The view in the receiver’s hierarchy whose
tag property matches the value in the tag parameter.

Discussion

This method searches the current view and all of its
subviews for the specified view.

So the solution for you is you need to specify unique tag for every label. And then use viewWithTag: and give the tag you specified.