迟到的派对，但我有一个工作的解决方案，创建一个菜单水平间距。在NSLayoutConstraint中使用==可以很容易地做到这一点

const float MENU_HEIGHT = 40;

- (UIView*) createMenuWithLabels: (NSArray *) labels
    // labels is NSArray of NSString
    UIView * backgroundView = [[UIView alloc]init];
    backgroundView.translatesAutoresizingMaskIntoConstraints = false;

    NSMutableDictionary * views = [[NSMutableDictionary alloc] init];
    NSMutableString * format = [[NSMutableString alloc] initWithString: @"H:|"];
    NSString * firstLabelKey;

    for(NSString * str in labels)
    {
        UILabel * label = [[UILabel alloc] init];
        label.translatesAutoresizingMaskIntoConstraints = false;
        label.text = str;
        label.textAlignment = NSTextAlignmentCenter;
        label.textColor = [UIColor whiteColor];
        [backgroundView addSubview: label];
        [label fixHeightToTopBounds: MENU_HEIGHT-2];
        [backgroundView addConstraints: [label fixHeightToTopBounds: MENU_HEIGHT]];
        NSString * key = [self camelCaseFromString: str];
        [views setObject: label forKey: key];
        if(firstLabelKey == nil)
        {
            [format appendString: [NSString stringWithFormat: @"[%@]", key]];
            firstLabelKey = key;
        }
        else
        {
            [format appendString: [NSString stringWithFormat: @"[%@(==%@)]", key, firstLabelKey]];
        }
    }

    [format appendString: @"|"];

    NSArray * constraints = [NSLayoutConstraint constraintsWithVisualFormat: (NSString *) format
                                                                               options: 0
                                                                               metrics: nil
                                                                                 views: (NSDictionary *) views];
    [backgroundView addConstraints: constraints];
    return backgroundView;
}

我一直在坐过山车，爱自动布局和讨厌它。喜欢它的关键似乎是接受以下几点:

接口构建器的编辑和“有帮助的”自动创建约束在大多数情况下几乎无用 创建类别来简化常见操作是一种拯救，因为代码是如此重复和冗长。

也就是说，你正在尝试的不是直接的，在接口构建器中很难实现。这在代码中很简单。这段代码，在viewDidLoad，创建和定位三个标签，你需要他们:

// Create three labels, turning off the default constraints applied to views created in code
UILabel *label1 = [UILabel new];
label1.translatesAutoresizingMaskIntoConstraints = NO;
label1.text = @"Label 1";

UILabel *label2 = [UILabel new];
label2.translatesAutoresizingMaskIntoConstraints = NO;
label2.text = @"Label 2";

UILabel *label3 = [UILabel new];
label3.translatesAutoresizingMaskIntoConstraints = NO;
label3.text = @"Label 3";

// Add them all to the view
[self.view addSubview:label1];
[self.view addSubview:label2];
[self.view addSubview:label3];

// Center them all horizontally
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label1 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label2 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label3 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0]];

// Center the middle one vertically
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label2 attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0]];

// Position the top one half way up
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label1 attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:label2 attribute:NSLayoutAttributeCenterY multiplier:0.5 constant:0]];

// Position the bottom one half way down
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:label3 attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:label2 attribute:NSLayoutAttributeCenterY multiplier:1.5 constant:0]];

我说过，这段代码通过UIView中的一些类别方法简化了很多，但为了清晰起见，这里我做了很多。

对于感兴趣的人来说，这个类别在这里，它有一个方法，可以沿着特定的轴均匀地间隔一个视图数组。

在InterfaceBuilder中解决这个问题非常简单:

设置居中标签(label2)为“水平容器中心”和“垂直容器中心”

选择居中标签和顶部标签(label1 + label2)，并为垂直间距添加两个约束。大于或等于最小间距的一个。小于或等于最大间距的一个。

中间的标签和底部的标签(label2 + label3)也是如此。

此外，您还可以添加两个约束label1 -顶部空间到SuperView和两个约束label2 -底部空间到SuperView。

结果是所有4个空格的大小变化相同。

另一种方法可能是让顶部和底部标签分别具有相对于视图顶部和底部的约束，并让中间视图分别具有相对于第一个和第三个视图的顶部和底部约束。

请注意，通过将视图拖到另一个视图附近，直到出现引导虚线，您可以对约束进行更多的控制——这些虚线表示将形成的两个对象之间的约束，而不是对象和父视图之间的约束。

在这种情况下，您可能希望将约束更改为“大于或等于”所需的值，而不是“等于”以允许它们调整大小。不确定这是否能达到你的目的。

Android has a method of chaining views together in its constraint based layout system that I wanted to mimic. Searches brought me here but none of the answers quite worked. I didn't want to use StackViews because they tend to cause me more grief down the line than they save up front. I ended up creating a solution that used UILayoutGuides placed between the views. Controlling their width's allows different types of distributions, chain styles in Android parlance. The function accepts a leading and trailing anchor instead of a parent view. This allows the chain to be placed between two arbitrary views rather than distributed inside of the parent view. It does use UILayoutGuide which is only available in iOS 9+ but that shouldn't be a problem anymore.

public enum LayoutConstraintChainStyle {
    case spread //Evenly distribute between the anchors
    case spreadInside //Pin the first & last views to the sides and then evenly distribute
    case packed //The views have a set space but are centered between the anchors.
}

public extension NSLayoutConstraint {

    static func chainHorizontally(views: [UIView],
                                  leadingAnchor: NSLayoutXAxisAnchor,
                                  trailingAnchor: NSLayoutXAxisAnchor,
                                  spacing: CGFloat = 0.0,
                                  style: LayoutConstraintChainStyle = .spread) -> [NSLayoutConstraint] {
    var constraints = [NSLayoutConstraint]()
    guard views.count > 1 else { return constraints }
    guard let first = views.first, let last = views.last, let superview = first.superview else { return constraints }

    //Setup the chain of views
    var distributionGuides = [UILayoutGuide]()
    var previous = first
    let firstGuide = UILayoutGuide()
    superview.addLayoutGuide(firstGuide)
    distributionGuides.append(firstGuide)
    firstGuide.identifier = "ChainDistribution\(distributionGuides.count)"
    constraints.append(firstGuide.leadingAnchor.constraint(equalTo: leadingAnchor))
    constraints.append(first.leadingAnchor.constraint(equalTo: firstGuide.trailingAnchor, constant: spacing))
    views.dropFirst().forEach { view in
        let g = UILayoutGuide()
        superview.addLayoutGuide(g)
        distributionGuides.append(g)
        g.identifier = "ChainDistribution\(distributionGuides.count)"
        constraints.append(contentsOf: [
            g.leadingAnchor.constraint(equalTo: previous.trailingAnchor),
            view.leadingAnchor.constraint(equalTo: g.trailingAnchor)
        ])
        previous = view
    }
    let lastGuide = UILayoutGuide()
    superview.addLayoutGuide(lastGuide)
    constraints.append(contentsOf: [lastGuide.leadingAnchor.constraint(equalTo: last.trailingAnchor),
                                    lastGuide.trailingAnchor.constraint(equalTo: trailingAnchor)])
    distributionGuides.append(lastGuide)

    //Space the according to the style.
    switch style {
    case .packed:
        if let first = distributionGuides.first, let last = distributionGuides.last {
            constraints.append(first.widthAnchor.constraint(greaterThanOrEqualToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(greaterThanOrEqualToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(equalTo: first.widthAnchor))
            constraints.append(contentsOf:
                distributionGuides.dropFirst().dropLast()
                    .map { $0.widthAnchor.constraint(equalToConstant: spacing) }
                )
        }
    case .spread:
        if let first = distributionGuides.first {
            constraints.append(contentsOf:
                distributionGuides.dropFirst().map { $0.widthAnchor.constraint(equalTo: first.widthAnchor) })
        }
    case .spreadInside:
        if let first = distributionGuides.first, let last = distributionGuides.last {
            constraints.append(first.widthAnchor.constraint(equalToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(equalToConstant: spacing))
            let innerGuides = distributionGuides.dropFirst().dropLast()
            if let key = innerGuides.first {
                constraints.append(contentsOf:
                    innerGuides.dropFirst().map { $0.widthAnchor.constraint(equalTo: key.widthAnchor) }
                )
            }
        }
    }

    return constraints
}

Here is a solution that will vertically center any number of subviews, even if they have unique sizes. What you want to do is make a mid-level container, center that in the superview, then put all the subviews in the container and arrange them with respect to one another. But crucially you also need to constrain them to the top and bottom of the container, so the container can be correctly sized and centered in the superview. By figuring the correct height from its subviews, the container can be vertically centered.

在本例中，self是位于所有子视图居中的父视图。

NSArray *subviews = @[ (your subviews in top-to-bottom order) ];

UIView *container = [[UIView alloc] initWithFrame:CGRectZero];
container.translatesAutoresizingMaskIntoConstraints = NO;
for (UIView *subview in subviews) {
    subview.translatesAutoresizingMaskIntoConstraints = NO;
    [container addSubview:subview];
}
[self addSubview:container];

[self addConstraint:[NSLayoutConstraint constraintWithItem:container attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual
                                                    toItem:self attribute:NSLayoutAttributeLeft multiplier:1.0f constant:0.0f]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:container attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual
                                                    toItem:self attribute:NSLayoutAttributeRight multiplier:1.0f constant:0.0f]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:container attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual
                                                    toItem:self attribute:NSLayoutAttributeCenterY multiplier:1.0f constant:0.0f]];

if (0 < subviews.count) {
    UIView *firstSubview = subviews[0];
    [container addConstraint:[NSLayoutConstraint constraintWithItem:firstSubview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual
                                                             toItem:container attribute:NSLayoutAttributeTop multiplier:1.0f constant:0.0f]];
    UIView *lastSubview = subviews.lastObject;
    [container addConstraint:[NSLayoutConstraint constraintWithItem:lastSubview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual
                                                             toItem:container attribute:NSLayoutAttributeBottom multiplier:1.0f constant:0.0f]];

    UIView *subviewAbove = nil;
    for (UIView *subview in subviews) {
        [container addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual
                                                                 toItem:container attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]];
        if (subviewAbove) {
            [container addConstraint:[NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual
                                                                     toItem:subviewAbove attribute:NSLayoutAttributeBottom multiplier:1.0f constant:10.0f]];
        }
        subviewAbove = subview;
    }
}