When developing for iOS, a lot of people confuse a UIView’s
center. This post will illustrate their difference. The images are taken from Stanford’s cs193p class.
bounds: The UIView’s size and location relative to itself.
frame: The UIView’s size and location relative to its superview.
center: The UIView’s center relative to its superview. To get center of your own view, you do
convertPoint(center, fromView: superview)