自动布局约束边界条件

Question

我希望view1右约束等于view2左约束，但如果view2移过view1的左边界（边界条件），则不希望这样做。 这是我的约束：

    view1.leftAnchor.constraint(equalTo: contentView.leftAnchor, constant: 0).isActive = true
    view1.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
    view1.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
    view1.leftAnchor.constraint(greaterThanOrEqualToSystemSpacingAfter: contentView.leftAnchor, multiplier: 1.0).isActive = true


   let rightBoundaryConstraint = view1.rightAnchor.constraint(equalTo: iew2.leftAnchor)

    rightBoundaryConstraint.priority = UILayoutPriority(999)
    rightBoundaryConstraint.isActive = true

我的怀疑是，这仍然不能100％地确定view1的位置。 我想念什么吗？

Answer 1

这表示“展开或收缩view1，因此其右边缘位于view2的左边缘”：

view1.rightAnchor.constraint(equalTo: view2.leftAnchor).isActive = true

添加：

view2.leftAnchor.constraint(greaterThanOrEqualTo: view1.leftAnchor).isActive = true

它说：“不要让view2的左边缘越过view1的左边缘”