KVO crash on UITextField initWithFrame
问题 A customer of my app sent me this strange crash report and I cannot figure out how this could ever crash. I cannot reproduce the problem myself, so am reliant on the crash report. It crashes on the following very simple line of code: UITextField *value = [[UITextField alloc] initWithFrame:frame]; The crash seems to be related to key-value-observing (KVO), but I am not doing anything with that here; it's a simply constructor! The only possibility I could see, is that another thread is writing