This tag should be used only on questions that are about Objective-C features or depend on code in the language.
I am attempting to send and receive messages through NSNotificationCenter in Objective-C. However, I haven't been able to find any …
ios objective-c nsnotificationcenterMy application uses an UITextView. Now I want the UITextView to have a placeholder similar to the one you can …
ios objective-c cocoa-touch uitextview placeholderI know how delegates work, and I know how I can use them. But how do I create them?
ios objective-c cocoa callback delegatesHow can I detect any text changes in a textField? The delegate method shouldChangeCharactersInRange works for something, but it did …
ios objective-c swift event-handling uitextfielddelegateIs there a way to call a block with a primitive parameter after a delay, like using performSelector:withObject:afterDelay: …
ios objective-c grand-central-dispatch objective-c-blocksI'm looking for the standard idiom to iterate over an NSArray. My code needs to be suitable for OS X 10.4+.
objective-c cocoa iteration nsarray enumerationHow do I add a touch event to a UIView? I try: UIView *headerView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.…
ios objective-c events uiview touchWhat does this line of code mean? label.frame = (inPseudoEditMode) ? kLabelIndentedRect : kLabelRect; The ? and : confuse me.
objective-c c syntax operators conditional-operatorI have a UIImageView and the objective is to scale it down proportionally by giving it either a height or …
objective-c cocoa-touchI am using ARC successfully in my project. However, I have encountered a few files (e.g., in unit tests …
objective-c xcode automatic-ref-counting manual-retain-release