Disable delegate methods depending on iOS version

Question

I'm using some UIPickerView delegate methods only for the brand-new-Ive-modified iOS under NDA, e.g.

-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view

I don't want to implement them for iOS6, to preserve default iOS behavior, so a condition inside the method won't work. How to do it?

This may be answered by the previous question http://stackoverflow.com/questions/3339722/check-iphone-ios-version — David Elliman, Sep 09 '13 at 14:33
If the delegate method is only declared for a particular version of iOS or later, it will only get called in those versions only. You'd have to deal with that and find another way. — Zen, Sep 09 '13 at 14:35
You could try swizzling method implementations or adding a mehtod implementation only for a certain OS version. — Christian Schnorr, Sep 09 '13 at 14:55

score 4 · Accepted Answer · answered Sep 09 '13 at 14:50

In your delegate, override respondsToSelector: and return NO in case of old OS:

- (BOOL)respondsToSelector:(SEL)selector
{
    if (selector == @selector(pickerView:viewForRow:forComponent:reusingView:))
        return MyFunctionThatChecksIosVersionIsMinimum7();
    return [super respondsToSelector:selector];
}

So you're implementing the delegate method normally. When the picker view is asking your delegate if it understands the message you're simply lying to it.

Disable delegate methods depending on iOS version

1 Answers1