UIAlertView button press causing crash, when all others work fine

I have an alertview which displays fine. In my header I've included the UIAlertViewDelegate, but for some reason whenever I click a button on the alert view my app crashes with a bad excess, saying that an unrecognized selector was sent.

Any ideas would be helpful. I have the exact same code running in other classes with no problem at all.

Here's my code:

    -(void)deletePatient
{
 NSLog(@"Delete");
 //Patient *patientInRow = (Patient *)[[self fetchedResultsController] objectAtIndexPath:cellAtIndexPath];
 NSMutableArray *visitsArray = [[NSMutableArray alloc] initWithArray:[patient.patientsVisits allObjects]];
 //cellAtIndexPath = indexPath;
 int visitsCount = [visitsArray count];
 NSLog(@"Visit count is %i", visitsCount);
 if (visitsCount !=0) 
 {
  //Display AlertView
  NSString *alertString = [NSString stringWithFormat:@"Would you like to delete %@'s data and all their visits and notes?", patient.nameGiven];
  UIAlertView *alert1 = [[UIAlertView alloc] initWithTitle:alertString message:nil delegate:self cancelButtonTitle:@"Yes" otherButtonTitles:@"No",nil];
  [alert1 show];
  [alert1 release];

 }
 else if (visitsCount ==0) 
 {
  //Do something else
 }

 [visitsArray release];

}

-(void)alertView:(UIAlertView*)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
 // the user clicked one of the OK/Cancel buttons
 if (buttonIndex == 0)
 {
  NSLog(@"Yes");

 }
 else
 {
  NSLog(@"No");
 }
}

So the best I can figure it out, its related to the fact I'm calling the deletePatient method from my UITableViewCell subClass, and passing along the patient object as I do so. Here's the code for passing it along

-(IBAction)deletePatient:(id)sender
{
 开发者_StackOverflow社区   NSLog(@"Delete Patient:%@",patient.nameGiven);
    PatientListTableViewController *patientList = [[PatientListTableViewController alloc] init];
    patientList.patient = patient;
    UITableView *tableView = (UITableView *)[self superview];
    tableView.scrollEnabled = YES;
    [patientList deletePatient];
    menuView.center = CGPointMake(160,menuView.center.y);
    [patientList release];
}

You set patientList object as delegate of UIAlertView instance, then released it. When user clicks alert button it calls [delegate alertView:self clickedButtonAtIndex:buttonIndex], but the delegate, patientList was already released and no longer exists. The variable delegate at this moment contain garbage, so not surprizing it have no alertView:clickedButtonAtIndex: selector;

Just release patientList object in alert alertView:clickedButtonAtIndex: method, or do patientList creating/releasing when you create/release outer class or simply use property:

// in *.h file:

...
PatientListTableViewController *patientList;
...
@property(retain) PatientListTableViewController *patientList;
...

// in *.m file: @synthesize patientList;

...
self.patientList =  [[PatientListTableViewController alloc] init];

Everything is fine with the code you provided. Unless something funky is happening with the patient object somewhere else, I'd say all looks good here.

Try using UIAlerView as autoreleased object like this;

UIAlertView *alert1 = [[UIAlertView alloc] initWithTitle:alertString message:nil delegate:self cancelButtonTitle:@"Yes" otherButtonTitles:@"No",nil] autorelease];
[alert1 show];