Generate labels and align in middle - swift

Question

How can i generate a random amount of labels and align them next to each other in the middle?
I have this code to generate an label:
var label = UILabel(frame: CGRectMake(5, 196, 35,45 ))
label.textAlignment = NSTextAlignment.Center
label.backgroundColor = UIColor.redColor()
label.text = "1";
label.tag = 5;
self.view.addSubview(label);
This work perfect, but how can i generate more than 1 label and set them next to each other in the middle?
like this:
The green things are my labels, and are align horizontally. How can i do this programmatically?

Answer 1

This will do it:
var lastLabel : UILabel?
var count = 1
#IBAction func addlabel(sender: AnyObject) {
var label = UILabel()
label.textAlignment = NSTextAlignment.Center
label.backgroundColor = UIColor.redColor()
label.text = count.description;
count++
label.tag = 5;
var centerX = NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0)
centerX.priority = 999
//This if you want to center it vertically also
var centerY = NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.CenterY, multiplier: 1, constant: 0)
var height = NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 35)
var width = NSLayoutConstraint(item: label, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 45)
label.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addSubview(label);
if let prevlabel = lastLabel {
var align = NSLayoutConstraint(item: prevlabel, attribute: NSLayoutAttribute.TrailingMargin, relatedBy: NSLayoutRelation.Equal, toItem: label, attribute: NSLayoutAttribute.LeadingMargin, multiplier: 1, constant: -20)
//Here just add the NSLayoutConstraint you want to apply, if its only horizontal then not add centerY
NSLayoutConstraint.activateConstraints([align, centerY, height, width, centerX])
}else {
NSLayoutConstraint.activateConstraints([centerX, centerY, height, width])
}
lastLabel = label
}