Making a round lable

//width and height are twice of  layer.cornerRadius

label.frame = CGRectMake(0, 0, 100, 100);
label.center = CGPointMake(160, 240);
label.alpha = 0.0;
   
  label.layer.cornerRadius = 50;
  label.clipsToBounds = YES;

Composite pattern

A design pattern that solves this kind of structural problem is
called the Composite patternWith the Composite pattern,  we can compose our strokes and dots into a tree structure
so that we can treat each of the nodes uniformly.

Observation Pattern in Objective-C

There are three steps to using key-value observation:

• Send the addObserver:forKeyPath:options:context: message

to each object that is being observed.

• Override the method observeValueForKeyPath:ofObject:chan

ge:content: in the class definition of the object that is doing the

observing.

• Override the dealloc method and remove the observer reference

in the class definition of the object that is observing.

The following are some high-level, conceptual questions to develop of Axure

• How is information organized and accessed on each screen in the case of Information Architecture?
• Where and how are key task flows initiated and ended?
• What are the main navigation systems?
• What common elements are shared across screens?
• How are common elements affected by a device size?