A delegate for resigning a UITextField when the return key is pressed. It's a corrected version of the code here: http://stackoverflow.com/questions/3186065/uitextfield-resign-first-responder-ios4

ResignOnReturnDelegate.m

@interface ResignOnReturnDelegate : NSObject <UITextFieldDelegate>

@end

@implementation ResignOnReturnDelegate

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if ([string isEqualToString:@"\n"]) {
        
        [textField resignFirstResponder];
        // Return FALSE so that the final '\n' character doesn't get added
        return NO;
    }
    
    // For any other character return TRUE so that the text gets added to the view
    return YES;
}

@end