UISwitch quick toggle multiple times.

Question

I was playing around my app and I was toggling a UISwitch really fast (who can resist?). So, I toggled it really fast for 10-15 times, an array that should contain the data from the table view cell that I have my switch in, either has extra copies of the same cell or just one copy (the correct case) or no data in it at all. The app works fine if it's toggled at normal speed.

I'm pretty sure this scenario won't really happen with my users, but I'm still curious as to why it's happening.

Thanks, Teja

Edit: Adding code. This method gets called each time the switch is toggled.

-(void)saveOptionChanged:(id) sender
{
UISwitch *sw = (UISwitch *) sender;
//int tag = current.tag;
BOOL status = (BOOL) [sw isOn];
NSInteger tag = sw.tag;
NSInteger row1 = tag%1000;
NSInteger section1 = (tag - row1)/1000;
DiagDetails *temp = [preferences getDiagElementAt:section1 row:row1];
temp.ICD9Code= [temp.ICD9Code stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
temp.ICD9Desc= [temp.ICD9Desc stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSLog(@"Adding %@ - %@",temp.ICD9Code, temp.ICD9Desc);
NSLog(@"tag = %ld, row = %ld, section = %ld",tag,row1,section1);
if(status) {
    BOOL returnVal = YES;
    returnVal = [currentPatient addICD9Code:temp];
    if(!returnVal) {
        UIAlertView *error = [[UIAlertView alloc] initWithTitle:@"Diagnosis add error" message:@"" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [error show];
        [error release];
        [sw setOn:NO];
    }
}
else {
    DiagDetails *temp = [preferences getDiagElementAt:section1 row:row1];
    [currentPatient removeICD9Code:temp.ICD9Code];
}
}

Answer 1

If I had to guess, you're trigging events so fast that they might coalesce or get skipped, so if you're implicitly setting state based on the number of times the event handler is called, you might get out of sync. (Instead you should be explicitly determining the state of the UISwitch -- on or off -- inside the event handler.) You'll have to show more code to be sure. At least the code for the event handler for the UISwitch changed state event.