Question

cocoa newbie here.
I try to take the input from keyboard and check it before it will be written on the nstextfield.
From searching i found keydown() and NSFirstResponder is what i need. But i cannot understand how to implement these things and generally how the thing with NSFirstResponder works.

Can someone help me with an example or some sources please?

Answer 1

dont get the raw events in a textfield. instead implement this delegate in your controller:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

return NO or YES to dis-/allow that change