Question

In Interface Builder, you have constraints that tell the app how to re-draw the screen when the device is rotated.

Is there a way to set those programmatically?

Answer 1

You need to set autoresizingMask of view.

It Specifies how a view is automatically resized. (This is what you set in Interface Builder.)

enum {
   UIViewAutoresizingNone                 = 0,
   UIViewAutoresizingFlexibleLeftMargin   = 1 << 0,
   UIViewAutoresizingFlexibleWidth        = 1 << 1,
   UIViewAutoresizingFlexibleRightMargin  = 1 << 2,
   UIViewAutoresizingFlexibleTopMargin    = 1 << 3,
   UIViewAutoresizingFlexibleHeight       = 1 << 4,
   UIViewAutoresizingFlexibleBottomMargin = 1 << 5
};
typedef NSUInteger UIViewAutoresizing;