IOS/Objective-C: Subview of Subview not displaying - ios

Question

I am trying to create a chart where a bar in the form of a UIView displays on top of a background UIView. I'd like both to display on top of the UIView for the whole screen. I have done this before successfully, but while I can get the first view to display, I somehow can't get my code to display the bar. Could it have something to do with setting the color? Or can anyone suggest why the second subview is not displaying.
My code:
//Make background box:
CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat screenWidth = screenRect.size.width;
CGFloat graphWidth = screenWidth-40;
CGFloat graphHeight = 160;
CGRect graphBounds =CGRectMake(20, 200, graphWidth, graphHeight);
float tableStartY = graphBounds.origin.y;
UIView *graphBox = [[UIView alloc] initWithFrame:graphBounds];
graphBox.backgroundColor = [UIColor colorWithRed:200.0/255.0 green:200.0/255.0 blue:200.0/255.0 alpha:0.2]; graphBox.layer.borderWidth = 1;
graphBox.layer.borderColor = [UIColor blueColor].CGColor;
//Make Bar
CGFloat barWidth = 20;
CGFloat barHeight = 100;
CGRect aBar = CGRectMake(20, tableStartY+1, barWidth, barHeight);
UIView *barView = [[UIView alloc] initWithFrame:aBar];
barView.backgroundColor = [UIColor blueColor];
barView.layer.borderWidth = 1;
barView.layer.borderColor = [UIColor redColor].CGColor;
// [graphBox addSubview:barView];
[self.view addSubview: graphBox];
If I run the above code, it displays the graphBox. If I add the bar directly to the view as a subView instead of the graphBox, the bar displays. However, if I uncomment out the line shown and add the barView first to the graphBox and then add the graphBox to the view, the barView does not display.
Thanks in advance for any suggestions.

Answer 1

If I understand correctly what you need to do, you should replace
CGRect aBar = CGRectMake(20, tableStartY+1, barWidth, barHeight);
with
CGRect aBar = CGRectMake(20, 1, barWidth, barHeight);
[edit: and obviously uncomment the addSubview line]

Answer 2

Perhaps this is an accident in your posted code, but you have specifically commented out where the barView would be added to the screen.
// [graphBox addSubview:barView];
In addition, as another answer lists, your offset is incorrect if you are adding barView to graphBox. If you add it to self.view instead, your offset is correct.
So, you've got two choices, depending on the containment you desire in your view hierarchy:
CGRect aBar = CGRectMake(20, 1, barWidth, barHeight);
// ...
[graphBox addSubview:barView];
or
CGRect aBar = CGRectMake(20, tableStartY+1, barWidth, barHeight);
// ...
[self.view addSubview: graphBox];
[self.view addSubview:barView];
Note that in the second option, the order is important to get the barView to display over top of the graphBox as they will be siblings.