UISwitch not being set properly based on values

Question

I am using several UISwitches and I can't get them to set correctly, for some odd reason.

I am pulling in JSON data which is just basically a bunch of integers in a certain sequence, based off of their values, I want a switch to be set to either on, or off. Here is part of the relevant code:

- (void)fetchData
{

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSData* data = [NSData dataWithContentsOfURL: [NSURL URLWithString:@"http://10.101.10.101/get/channels"]];

        NSError* error;

        LightingData = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
        idData = [LightingData valueForKey:@"level"];

        NSLog(@"Lighting Values: %@", [idData objectAtIndex:19]);

        dispatch_async(dispatch_get_main_queue(), ^{

       });
    });

}

- (void)dataCheck
{
    int x = 100;

    if ([idData objectAtIndex:19 == x])
    {
        [fieldsOverheadStatus setOn:YES];
    }
}

The dataCheck method continues for a while, setting about 20 switches.

I have all of my switches set to default as "off", but when I run the app, they all show as being "on".

I set breakpoints to see if the dataCheck method gets called, and it does. As you can see, I stuck a log in to see what the value of objectAtIndex:19 is and the value that is returned is 0 (not null). I checked the contents of idData and all of the values are correctly gotten.

Can anyone tell me why my switches are being changed, even when they shouldn't be? What am I doing wrong?

Let me know if anymore code is needed.

Answer 1

You’re checking the object in idData at the index (19 == x), i.e. false/NO, i.e. 0; the object at index 0 is non-nil, so you’re always setting the switch on. That line should probably be:

if ([[idData objectAtIndex:19] intValue] == x)