c# - 如何与约束水平对齐？

Question

我怎样才能水平对齐三个元素[A B C]一个又一个有约束条件？

public static void AddConstraintsElements(UIView View, UIView element, UIView element2, UIView element3)
        {
            NSLayoutConstraint.ActivateConstraints(new[] {
                element.TopAnchor.ConstraintGreaterThanOrEqualTo(View.TopAnchor, constant: 20),
                element.LeadingAnchor.ConstraintGreaterThanOrEqualTo(View.LeadingAnchor, constant: 100),
                element.WidthAnchor.ConstraintGreaterThanOrEqualTo(View.WidthAnchor, 1),
                element.HeightAnchor.ConstraintGreaterThanOrEqualTo(View.HeightAnchor, 1),

                element2.BottomAnchor.ConstraintGreaterThanOrEqualTo(View.TopAnchor, constant: 20),
                element2.TrailingAnchor.ConstraintGreaterThanOrEqualTo(View.LeadingAnchor, constant: 120),
                element2.WidthAnchor.ConstraintGreaterThanOrEqualTo( 1),
                element2.HeightAnchor.ConstraintGreaterThanOrEqualTo( 1),

                element3.BottomAnchor.ConstraintGreaterThanOrEqualTo(View.TopAnchor, constant: 20),
                element3.TrailingAnchor.ConstraintGreaterThanOrEqualTo(View.LeadingAnchor, constant: 120),
                element3.WidthAnchor.ConstraintGreaterThanOrEqualTo( 1),
                element3.HeightAnchor.ConstraintGreaterThanOrEqualTo( 1)
            });
        }

如果是第一元素和第二元素，请移除第三个元素
:



我试过了但是没用

element1.WidthAnchor.ConstraintEqualTo(25).Active = true;
            element1.HeightAnchor.ConstraintEqualTo(element1.WidthAnchor).Active = true;

            element2.WidthAnchor.ConstraintEqualTo(30).Active = true;
            element2.HeightAnchor.ConstraintEqualTo(30).Active = true;



            element1.TrailingAnchor.ConstraintEqualTo(element2.LeadingAnchor).Active = true;

            element1.TopAnchor.ConstraintEqualTo(View.TopAnchor, 15).Active = true;
            element2.TopAnchor.ConstraintEqualTo(View.TopAnchor, 15).Active = true;

            element1.LeftAnchor.ConstraintEqualTo( View.CenterXAnchor).Active = true;
            element2.RightAnchor.ConstraintEqualTo(View.RightAnchor).Active = true;

Answer 1

假设您要像这样对齐它们:

+-----------------------------------------------+
|                       ^                       |
|                      120                      |
|                       v                       |
|       +---------++---------++---------+       |
|       |         ||         ||         |       |
|       |    A    ||    B    ||    C    |       |
|       |         ||         ||         |       |
|       +---------++---------++---------+       |
|                                               |
|                                               |
|                                               |

物品居中并从顶部指向120点，它们的宽度和高度固定。您可以执行以下操作:

// set widths and heights
a.WidthAnchor.ConstraintEqualTo(25).Active = true;
a.HeightAnchor.ConstraintEqualTo(a.WidthAnchor).Active = true;

b.WidthAnchor.ConstraintEqualTo(25).Active = true;
b.HeightAnchor.ConstraintEqualTo(b.WidthAnchor).Active = true;

c.WidthAnchor.ConstraintEqualTo(25).Active = true;
c.HeightAnchor.ConstraintEqualTo(c.WidthAnchor).Active = true;

// align B view as the middle view
b.CenterXAnchor.ConstraintEqualTo(View.CenterXAnchor).Active = true;

// align A to left of B
a.TrailingAnchor.ConstraintEqualTo(b.LeadingAnchor).Active = true;

// align C to right of B
c.LeadingAnchor.ConstraintEqualTo(b.TrailingAnchor).Active = true;

// align A, B and C, 120 points from the top
a.TopAnchor.ConstraintEqualTo(View.TopAnchor, 120).Active = true;
b.TopAnchor.ConstraintEqualTo(View.TopAnchor, 120).Active = true;
c.TopAnchor.ConstraintEqualTo(View.TopAnchor, 120).Active = true;