自动限制约束边界条件

Question

我希望View1右约束等于View2左约束，但如果View2移动到View1(边界条件(的左移动。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

我的疑问是，这仍然无法确定100％确定性的View1。我想念什么吗？

Answer 1

这说"展开或合同视图1，因此其右边在View2的左边缘"：

：

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

添加此：

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

说："不要让View2的左边走过View1的左边缘"