//子控件自身高度
ConsBTN控件名字
// 子控件自身高度
ConsBTN.translatesAutoresizingMaskIntoConstraints = false
// 宽
let width:NSLayoutConstraint = NSLayoutConstraint(item: ConsBTN, attribute: NSLayoutAttribute.width, relatedBy:NSLayoutRelation.equal, toItem:nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier:0.0, constant:70)
ConsBTN.addConstraint(width)//自己添加约束
//高
let height:NSLayoutConstraint = NSLayoutConstraint(item: ConsBTN, attribute: NSLayoutAttribute.height, relatedBy:NSLayoutRelation.equal, toItem:nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier:0.0, constant:70)
ConsBTN.addConstraint(height)//自己添加约束
