set UITextField as non editable - Objective C

Question

    [Number.editable = NO];
    [Number resignFirstResponder];
    [Password.editable = NO];
    [Password resignFirstResponder];

I am getting the

Answer 1

Returning NO from shouldChangeCharactersInRange would be better choice because if text is longer than the textfield width, then above solution will give problem, because user won't be able to see all text(i.e. text hidden beyond the text field width)