Can I add a subview inside a subview?

Question

I have added a view inside ViewController using [self.view addSubview:newView]. newView is a UIView type object. Inside newView I added added a few views using [self addSubview:polyg];. Polygs also inherit from UIView. But they never get drawn. drawRect:(CGRect)rect is never called.

I'm new to iOS and have no idea what I'm doing wrong.

It probably has something to do with the fact that I did not use self.view when adding views to newView. I can't even use self.view inside newView.

how can I make this work?

edit: When i create these polyg objects I'm using initWithFrame and sending newView's frame, like this: [[Polyg alloc] initWithFrame:self.frame]; Could this be the cause? Polyg is going to be a movable and resizable polygon, so I figured each should be able to draw on the entire screen.

edit: I created a method inside newView called touchX:Y that is called from the viewController whenever I touch my finger on the screen. Inside I wrote this: NSLog(@"subview = %i", self.subviews.count);. Whenever I touch the screen I see this on the console: subview = 89 so I'm pretty sure the subviews were added to newView.

I tried adding this to the same touchX:Y method:

        for (UIView* subview in self.subviews) {
            [subview setNeedsDisplay];
        }

But the subviews' drawRect is never called.

You can add nested subviews as deep as you need. Just remember that a view's frame is always relative to its immediate superview (parent view). — rmaddy
Yes, you can add subviews to subviews. If you really called your method DrawRect, it won't get called. The name of the method must be drawRect:. It must be correctly capitalized and must take one CGRect argument. If you did call it drawRect:, how do you know it's not being called? — rob mayoff
- (void)drawRect:(CGRect)rect { // Drawing code NSLog(@"drawRect!"); } drawRect never shows up on the console. (edited the question with the correct method name) — HSNN
If newView is a view, it hasn't a property called view. View controllers have it. — Ramy Al Zuhouri
It is a view and I can't use self.view inside it. Is that the problem? I can add subViews to the viewController but can't add a subView to a subView? — HSNN

Liye Zhang Liye Zhang · Accepted Answer · 2013-06-23T23:54:32

The most likely possibility is that newView is either completely off the screen or have a size of (0,0). Right before you add the ployg subviews, use the debugger to print out the frame of newView.

Can I add a subview inside a subview?

1 Answers