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;
}

正确和最简单的方法是使用堆栈视图。

将标签/视图添加到堆栈视图:

选择堆栈视图并设置分布为相等间距:

在堆栈视图中添加最近邻居约束的空格，并更新帧:

为所有标签添加高度约束(可选)。仅对没有固有大小的视图需要)。例如，标签在这里不需要高度约束，只需要设置numberOfLines = 3或0。

享受预览:

我可以在IB中完全解决这个问题:

使约束使每个子视图的中心Y对齐到父视图的下边缘。 将每个约束的乘数设置为1/2n, 3/2n, 5/2n，…，n-1/2n，其中n是要分布的子视图的数量。

因此，如果您有三个标签，请将每个约束的乘数设置为0.1666667、0.5、0.833333。

大多数解决方案都依赖于项目的奇数，这样你就可以把中间的项目放在中间。如果你有偶数个项目想要平均分配呢?这是一个更一般的解。这个类别将沿垂直或水平轴均匀分布任意数量的项目。

在它们的父视图中垂直分布4个标签的示例:

[self.view addConstraints:
     [NSLayoutConstraint constraintsForEvenDistributionOfItems:@[label1, label2, label3, label4]
                                        relativeToCenterOfItem:self.view
                                                    vertically:YES]];

NSLayoutConstraint + EvenDistribution.h

@interface NSLayoutConstraint (EvenDistribution)

/**
 * Returns constraints that will cause a set of views to be evenly distributed horizontally
 * or vertically relative to the center of another item. This is used to maintain an even
 * distribution of subviews even when the superview is resized.
 */
+ (NSArray *) constraintsForEvenDistributionOfItems:(NSArray *)views
                             relativeToCenterOfItem:(id)toView
                                         vertically:(BOOL)vertically;

@end

NSLayoutConstraint + EvenDistribution.m

@implementation NSLayoutConstraint (EvenDistribution)

+(NSArray *)constraintsForEvenDistributionOfItems:(NSArray *)views
                           relativeToCenterOfItem:(id)toView vertically:(BOOL)vertically
{
    NSMutableArray *constraints = [NSMutableArray new];
    NSLayoutAttribute attr = vertically ? NSLayoutAttributeCenterY : NSLayoutAttributeCenterX;

    for (NSUInteger i = 0; i < [views count]; i++) {
        id view = views[i];
        CGFloat multiplier = (2*i + 2) / (CGFloat)([views count] + 1);
        NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:view
                                                                      attribute:attr
                                                                      relatedBy:NSLayoutRelationEqual
                                                                         toItem:toView
                                                                      attribute:attr
                                                                     multiplier:multiplier
                                                                       constant:0];
        [constraints addObject:constraint];
    }

    return constraints;
}

@end

Swift 3版本

let _redView = UIView()
        _redView.backgroundColor = UIColor.red
        _redView.translatesAutoresizingMaskIntoConstraints = false

        let _yellowView = UIView()
        _yellowView.backgroundColor = UIColor.yellow
        _yellowView.translatesAutoresizingMaskIntoConstraints = false

        let _blueView = UIView()
        _blueView.backgroundColor = UIColor.blue
        _blueView.translatesAutoresizingMaskIntoConstraints = false

        self.view.addSubview(_redView)
        self.view.addSubview(_yellowView)
        self.view.addSubview(_blueView)

        var views = ["_redView": _redView, "_yellowView": _yellowView, "_blueView":_blueView]

        var nslayoutConstraint_H = NSLayoutConstraint.constraints(withVisualFormat: "|->=0-[_redView(40)]->=0-[_yellowView(40)]->=0-[_blueView(40)]->=0-|", options: [.alignAllTop, .alignAllBottom], metrics: nil, views: views)
        self.view.addConstraints(nslayoutConstraint_H)

        var nslayoutConstraint_V = NSLayoutConstraint.constraints(withVisualFormat: "V:[_redView(60)]", options: NSLayoutFormatOptions.init(rawValue: 0), metrics: nil, views: views)
        self.view.addConstraints(nslayoutConstraint_V)


        let constraint_red = NSLayoutConstraint.init(item: self.view, attribute: .centerY, relatedBy: .equal, toItem: _redView, attribute: .centerY, multiplier: 1, constant: 0)
        self.view.addConstraint(constraint_red)

        let constraint_yellow = NSLayoutConstraint.init(item: self.view, attribute: .centerX, relatedBy: .equal, toItem: _yellowView, attribute: .centerX, multiplier: 1, constant: 0)
        self.view.addConstraint(constraint_yellow)

        let constraint_yellow1 = NSLayoutConstraint.init(item: _redView, attribute: .centerX, relatedBy: .equal, toItem: _yellowView, attribute: .leading, multiplier: 0.5, constant: 0)
        self.view.addConstraint(constraint_yellow1)

        let constraint_yellow2 = NSLayoutConstraint.init(item: _blueView, attribute: .centerX, relatedBy: .equal, toItem: _yellowView, attribute: .leading, multiplier: 1.5, constant: 40)
        self.view.addConstraint(constraint_yellow2)

我找到了一个完美而简单的方法。自动布局不允许你平等地调整空间大小，但它允许你平等地调整视图大小。简单地在你的字段之间放置一些不可见的视图，并告诉自动布局保持它们相同的大小。它工作得很完美!

但有一件事值得注意;当我在界面设计器中减小尺寸时，有时它会混淆，在原来的地方留下一个标签，如果大小改变了奇数个量，它就会发生冲突。除此之外，它工作得很完美。

编辑:我发现冲突成了一个问题。因此，我删除了其中一个间距约束，并将其替换为两个约束，一个大于或等于，一个小于或等于。两者的大小相同，优先级比其他约束低得多。结果没有进一步的冲突。