How do I send the iOS user an instant local notification? - objective-c

Question

I simply want a notification to pop up when the user presses a button. No servers or timers needed. All the tutorials I can find seem to involve one of these two.

Answer 1

Maybe something like this:
-(IBAction) buttonPressed: (UIButton *)sender{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: [NSString stringWithFormat:#"You pressed button %#", sender.tag]
message: #"message"
delegate: self
cancelButtonTitle: #"Ok"
otherButtonTitles: nil]];
[alert show];
}
It would look something like this:
You can also customize the alert view a bit, so it could potentially have a textfield for text entry:
With UIAlertViews, you can also implement protocol methods like – alertView:clickedButtonAtIndex: and – alertView:willDismissWithButtonIndex:to perform different actions depending on which alert button they pressed.
Here's a good tutorial on UIAlertViews and implementing their protocol methods: http://mobile.tutsplus.com/tutorials/iphone/uialertview/.
If you don't want to use UIAlertViews and instead want a more customizable modal view, check out these two great libraries called UAModalPanel and MJPopupViewController. You can check out the links for images, demos, and more info on the two libraries, including links to their github pages where you can download them.
Hope this helps!

Answer 2

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title message:message delegate:delegate cancelButtonTitle:cancelMessage];
[alertView show];

Answer 3

It is important to make sure the alert is shown on the main thread, where all the UI is handled. Otherwise you may get some weird errors and/or crashes. You can use GCD to dispatch to the main thread:
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Alert Test"
message:#"This is an alert test."
delegate:self
cancelButtonTitle:#"Cancel"
otherButtonTitles:#"OK",
nil];
dispatch_async(dispatch_get_main_queue(), ^{
[alert show];
});