Move button after adding subview - ios

Question

Edited following comments below - using constraints to control the layout.
I am trying to add/remove views controllers, which are set up within the storyboard, via a button. The button and any previously added views should move down the screen as per the following visual format strings:
Optional("V:|-50-[viewXIB0(100)]-30-[buttonKey]")
Optional("V:|-50-[viewXIB1(100)]-30-[viewXIB0(100)]-30-[buttonKey]")
Optional("V:|-50-[viewXIB2(100)]-30-[viewXIB1(100)]-30-[viewXIB0(100)]-30-[buttonKey]")
(This is the println output of the visual format string fed into NSLayoutConstraint.constraintsWithVisualFormat.)
Thanks already to the comments below, the view does appear each time the button is pressed, and moves down the page correctly. However, the spacing between the superview and top view is zero - without margin. A similar issue also when additional views are added - each one gets tucked underneath the spacing. The bottom spacing is greater than the desired 30. And, after a few inserts, even weirder things start to happen towards the top of the screen.
There are no constraint errors on build or running. When my computer is running super slow, I do see it appear briefly in the correct place, and then snap to the top of the screen. I think I can hear it laughing at me too, but that might be a joke. Autolayout is enabled in both View Controllers.
The full method I'm using to add the view from a touch up inside button is:
#IBAction func addVCBenj(sender: AnyObject)
{
// remove original constraint from button
if (topConstraintBenjV != nil)
{
view.removeConstraint(topConstraintBenjV)
topConstraintBenjV = nil
println("addVCBen constraints removed")
}
// remove previous constraints as views are added
if (constraintV != nil)
{
view.removeConstraints(constraintV!)
println("removed")
}
// instantiate add add the view within the storyboard VC
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let myVC = storyboard.instantiateViewControllerWithIdentifier("VCtoInsert") as UIViewController
view.addSubview(myVC.view)
// create and add a unique key for each view in the dictionary of views
viewsDictionaryKey = "\(viewsDictionaryString)\(viewsDictionaryCounter)"
viewsDictionaryCounter += 1
viewsDictionary[viewsDictionaryKey!] = myVC.view
// create the visual format string for layout
suffixVisualFormatString_V = "[" + viewsDictionaryKey! + "(100)]-30-" + suffixVisualFormatString_V
visualFormatString_V = prefixVisualFormatString_V + suffixVisualFormatString_V
println(visualFormatString_V)
// create and add horizontal and vertical constraints
let constraintH = NSLayoutConstraint.constraintsWithVisualFormat("H:[\(viewsDictionaryKey!)(>=300)]", options: NSLayoutFormatOptions(0), metrics: metricsDictionary, views: viewsDictionary)
myVC.view.setTranslatesAutoresizingMaskIntoConstraints(false)
constraintV = NSLayoutConstraint.constraintsWithVisualFormat(visualFormatString_V!, options: NSLayoutFormatOptions(0), metrics: metricsDictionary, views: viewsDictionary)
self.view.addConstraints(constraintV!)
self.view.addConstraints(constraintH)
}
I've seen the WWDC videos, and searched for a similar problem, but in truth, I'm now so confused, I don't know what to even search for anymore.

Answer 1

As per a comment by BooRanger, by adding an IBOutlet to the top and bottom contraints, it was possible to manipulate the views each time a button was pressed. Ultimately, however, collection views are an easier way to add and remove views.