Retrieving tapped button on UIAlertView - objective-c

Question

I had this code running on my app, and now on iOS 6 it crashes my app:
// Another method
[NSThread detachNewThreadSelector:#selector(askServerForNFeID)
toTarget:self withObject:nil];
- (void)askServerForNFeID {
if ([response isEqualToString:#"XXXX"]) {
NSString *responseMessage = [NSString stringWithFormat:
NSLocalizedString(#"Autorizado o Uso da NFe\n para chave:\n%#", #""),
[invoiceInfo NFeID]];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:NSLocalizedString(#"Sefaz respondeu:", #"")
message:responseMessage
delegate:self
cancelButtonTitle:NSLocalizedString(#"OK", #"")
otherButtonTitles:nil];
[alert show];
[alert release];
}
}
I have learned that calling the alert from a second thread causes the crash, and so I changed my code to call the alert from the main thread like this:
if ([response isEqualToString:#"XXXX"]) {
[self performSelectorOnMainThread:#selector(showAlertHelper:)
withObject:[[NSArray alloc] initWithObjects:
NSLocalizedString(#"Não posso seguir em frente", #""),
NSLocalizedString(#"Você usou .....", #""), #"Fechar", #"Comprar", nil]
waitUntilDone:YES];
Note I am parsing the title, message and buttons as a list to showAlertHelper...
-(void)showAlertHelper:(NSArray*)theArray{
if ([[theArray objectAtIndex:3] isEqualToString:#""]) {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:nil
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:nil];
[alertView show];
[alertView release];
}
else {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:nil
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:[theArray objectAtIndex:3], nil];
[alertView show];
[alertView release];
}
}
My problem now, is that I had this handler to catch the button that was tapped, and it doesn't work any more. It just isn't called:
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
NSString *title = [alertView buttonTitleAtIndex:buttonIndex];
if ([title isEqualToString:NSLocalizedString(#"Comprar", #"")]) {
// Do stuff to buy credits...
} else if ([title isEqualToString:NSLocalizedString(#"Fechar", #"")]) {
NSLog(#"Fechar was selected.");
}
else if ([title isEqualToString:NSLocalizedString(#"Criar conta", #"")]) {
// Do stuff to create an account...
}
}

Answer 1

The problem is that in your re-written method, you set the delegate to nil instead of self. As a result, the alertView:clickedButtonAtIndex: delegate method isn't called. Change your code to the following: by specifying self in the delegate: parameter:
-(void)showAlertHelper:(NSArray*)theArray{
if ([[theArray objectAtIndex:3] isEqualToString:#""]) {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:self
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:nil];
[alertView show];
[alertView release];
} else {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:self
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:[theArray objectAtIndex:3], nil];
[alertView show];
[alertView release];
}
}

Answer 2

You removed the delegate from the creation method of your UIAlertView
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:nil
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:[theArray objectAtIndex:3], nil];
should be
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle:[theArray objectAtIndex:0]
message:[theArray objectAtIndex:1]
delegate:self
cancelButtonTitle:[theArray objectAtIndex:2]
otherButtonTitles:[theArray objectAtIndex:3], nil];