如何以编程方式约束第一视图宽度约束值等于第二视图前导空间等等？

Question

下面的代码我有多个视图划分所有视图相等的宽度，并且还成功地划分所有视图的宽度相等，但不会根据前一个视图划分空间增加。请解决此问题.customView是我的超级视图。

for i in 0..<countNoOfViews{
            var customView1:UIView!
            customView1 = UIView(frame: CGRect.zero)
            customView1.translatesAutoresizingMaskIntoConstraints = false
            customView.addSubview(customView1)


            let widthConstraint1 = NSLayoutConstraint(item: customView1, attribute: .width, relatedBy: .equal,toItem: customView, attribute: .width, multiplier: 1/CGFloat(countNoOfViews), constant: 0)

            let leadingConstraint = NSLayoutConstraint(item: customView1, attribute: .leading, relatedBy: .equal, toItem: customView, attribute: .leading, multiplier: 1.0, constant: 0)


            let topConstraint = NSLayoutConstraint(item: customView1, attribute: .top, relatedBy: .equal,toItem: customView, attribute: .top, multiplier: 1.0, constant: 0)

            let bottomConstraint = NSLayoutConstraint(item: customView1, attribute: .bottom, relatedBy: .equal,toItem: customView, attribute: .bottom, multiplier: 1.0, constant: 0)

            let trailingConstraint2 = NSLayoutConstraint(item: customView1, attribute: .trailing, relatedBy: .equal, toItem: customView, attribute: .trailing, multiplier:1.0, constant: 0)

            if i == 0{
                customView1.backgroundColor = UIColor.black
                customView.addConstraints([topConstraint,bottomConstraint,leadingConstraint,widthConstraint1])
            }else if i == 1{
                customView1.backgroundColor = UIColor.red
                 customView.addConstraints([leadingConstraint,topConstraint,bottomConstraint,widthConstraint1])
            }else if i == 2{
                customView1.backgroundColor = UIColor.purple
                customView.addConstraints([leadingConstraint,topConstraint,bottomConstraint,trailingConstraint2])
            }
        }