Why is the following UIAlertView code not working - objective-c

Question

I'm trying to get the following working, this example appears on a few websites but i just can't seem to get it working.
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Yes, like this" message:#"What are you looking at?" cancelButtonTitle:#"Leave me alone" otherButtonTitles:#"Button 1",#"Button 2",nil];
[alert showWithDismissHandler:^(NSInteger selectedIndex, BOOL didCancel) {
if (didCancel) {
NSLog(#"User cancelled");
return;
}
switch (selectedIndex) {
case 1:
NSLog(#"1 selected");
break;
case 2:
NSLog(#"2 selected");
break;
default:
break;
}
}];
The warnings I'm getting are
No visible #interface for 'UIAlertView' declares the selector 'initWithTitle:message:cancelButtonTitle:otherButtonTitles:'
No visible #interface for 'UIAlertView' declares the selector 'showWithDismissHandler:'
Properly a really daft question but what am i missing.
Thanks

Answer 1

The signature is not correct. You missed delegate.
– initWithTitle:message:delegate:cancelButtonTitle:otherButtonTitles:
The standard UIAlertView does not have showWithDismissHandler method. If you copied some code from internet, likely you will need to download some third party package that supports UIAlertView with block callback (there are quite a few of them).

Answer 2

Yes, Peter is right! The first warning is because the signature is not correct:
– initWithTitle:message:delegate:cancelButtonTitle:otherButtonTitles:
and what you trying to do here is to do something when the alertview is dismissed and the method you are using is not available. Implement UIAlertViewDelegate and then use any of these methods to do what you are trying to do here.
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
Here's the link to UIAlertView delegate reference:
http://developer.apple.com/library/ios/documentation/uikit/reference/UIAlertViewDelegate_Protocol/UIAlertViewDelegate/UIAlertViewDelegate.html

Answer 3

Are you using something like UBAlertView, by any chance? If so, you need to instantiate a UBAlertView, not a UIAlertView:
UBAlertView *alert = [[UBAlertView alloc] initWithTitle:#"Yes, like this"
message:#"What are you looking at?"
cancelButtonTitle:#"Leave me alone"
otherButtonTitles:#"Button 1",#"Button 2",nil];
[alert showWithDismissHandler:^(NSInteger selectedIndex, BOOL didCancel) {
... etc ...
(I like to put line breaks in long method calls to make them more readable.)