//Case1 ▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽
self.view.addSubview(lblCase1)
let t = NSLayoutConstraint(item: lblCase1, attribute: .top, relatedBy: .equal, toItem: self.view, attribute: .top, multiplier: 1.0, constant: 50)
let l = NSLayoutConstraint(item: lblCase1, attribute: .leading, relatedBy: .equal, toItem: self.view, attribute: .leading, multiplier: 1.0, constant: 50)
let r = NSLayoutConstraint(item: lblCase1, attribute: .trailing, relatedBy: .equal, toItem: self.view, attribute: .trailing, multiplier: 1.0, constant: -50)
let h = NSLayoutConstraint(item: lblCase1, attribute: .height, relatedBy: .equal, toItem: self.view, attribute: .height, multiplier: 0.0, constant: 50)
self.view.addConstraints([t, l, r, h])
//△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△
//Case2 ▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽
view.addSubview(lblCase2)
view.visualFormata(format: "H:|-50-[v0]-50-|", views: lblCase2)
view.visualFormata(format: "V:|-[v0]-50-[v1(50)]", views: lblCase1, lblCase2)
//△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△
//Case3 ▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽
view.addSubview(lblCase3)
NSLayoutConstraint.activate([
lblCase3.topAnchor.constraint(equalTo: lblCase2.bottomAnchor, constant: 50),
lblCase3.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 50),
lblCase3.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -50),
lblCase3.heightAnchor.constraint(equalToConstant: 50),
])
//△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△
//Case4 ▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽▽
view.addSubview(lblCase4)
NSLayoutConstraint.activate([
lblCase4.T.constraint(equalTo: lblCase3.B, constant: 50),
lblCase4.L.constraint(equalTo: view.L, constant: 50),
lblCase4.R.constraint(equalTo: view.R, constant: -50),
lblCase4.H.constraint(equalToConstant: 50),
])
//△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△△