How can I hide UIBarbuttonItem on UIToolbar for small size class?

Question

It's so pity that UIToolbar doesn't support size classes for UIBarbuttonItem elements. How can I hide UIBarbuttonItem on UIToolbar for small size class?

Answer 1

First, add this:

- (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection {
    [super traitCollectionDidChange:previousTraitCollection];
    if ((self.traitCollection.verticalSizeClass != previousTraitCollection.verticalSizeClass)
        || (self.traitCollection.horizontalSizeClass != previousTraitCollection.horizontalSizeClass)) {
        [self setupToolbar:self.traitCollection.horizontalSizeClass];
    }
}

And then recreate toolbar items:

    if (horizontalSizeClass == UIUserInterfaceSizeClassCompact) {
        mainItems = [NSArray arrayWithObjects:..., nil];
    } else {
        mainItems = [NSArray arrayWithObjects:..., nil];
    }
    [mainToolbar setItems:mainItems animated:NO];