自动布局让我的生活很困难。从理论上讲,当我转换的时候,它会非常有用,但我似乎一直在与它作斗争。
我做了一个演示项目来寻求帮助。有人知道如何使视图之间的空间增加或减少均匀,每当视图调整大小?
下面是三个标签(手动垂直对齐):
我想要的是,当我旋转时,它们均匀地调整间距(而不是视图大小)。默认情况下,顶部和底部视图向中心挤压:
自动布局让我的生活很困难。从理论上讲,当我转换的时候,它会非常有用,但我似乎一直在与它作斗争。
我做了一个演示项目来寻求帮助。有人知道如何使视图之间的空间增加或减少均匀,每当视图调整大小?
下面是三个标签(手动垂直对齐):
我想要的是,当我旋转时,它们均匀地调整间距(而不是视图大小)。默认情况下,顶部和底部视图向中心挤压:
当前回答
基于Ben Dolman的回答,这将更均匀地分配视图(使用填充等):
+(NSArray *)constraintsForEvenDistributionOfItems:(NSArray *)views
relativeToCenterOfItem:(id)toView vertically:(BOOL)vertically
{
NSMutableArray *constraints = [NSMutableArray new];
NSLayoutAttribute attr = vertically ? NSLayoutAttributeCenterY : NSLayoutAttributeCenterX;
CGFloat min = 0.25;
CGFloat max = 1.75;
CGFloat d = (max-min) / ([views count] - 1);
for (NSUInteger i = 0; i < [views count]; i++) {
id view = views[i];
CGFloat multiplier = i * d + min;
NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:view
attribute:attr
relatedBy:NSLayoutRelationEqual
toItem:toView
attribute:attr
multiplier:multiplier
constant:0];
[constraints addObject:constraint];
}
return constraints;
}
其他回答
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
}
是的,你可以只在接口构建器中这样做,而不需要编写代码——需要注意的是,你是在调整标签的大小,而不是分配空白。在本例中,将标签2的X和Y对齐到父视图,使其固定在中心。然后将标签1的垂直空间设置为superview,标签2设置为standard,重复标签3。在设置标签2之后,设置标签1和3最简单的方法是调整它们的大小,直到它们断开。
这是水平显示,注意标签1和2之间的垂直空间被设置为标准:
这是竖屏版本:
我意识到,由于标签之间的标准空间和父视图的标准空间之间的差异,它们在基线之间不是绝对100%等间距的。如果这让您感到困扰,可以将大小设置为0而不是standard
我知道距离第一个答案已经有一段时间了,但我刚刚遇到了同样的问题,我想分享我的解决方案。为了子孙后代……
我在viewDidLoad上设置了视图:
- (void)viewDidLoad {
[super viewDidLoad];
cancelButton = [UIButton buttonWithType: UIButtonTypeRoundedRect];
cancelButton.translatesAutoresizingMaskIntoConstraints = NO;
[cancelButton setTitle:@"Cancel" forState:UIControlStateNormal];
[self.view addSubview:cancelButton];
middleButton = [UIButton buttonWithType: UIButtonTypeRoundedRect];
middleButton.translatesAutoresizingMaskIntoConstraints = NO;
[middleButton setTitle:@"Middle" forState:UIControlStateNormal];
[self.view addSubview:middleButton];
nextButton = [UIButton buttonWithType: UIButtonTypeRoundedRect];
nextButton.translatesAutoresizingMaskIntoConstraints = NO;
[nextButton setTitle:@"Next" forState:UIControlStateNormal];
[self.view addSubview:nextButton];
[self.view setNeedsUpdateConstraints];
}
然后,在updateViewConstrains上,首先删除所有约束,然后创建视图字典,然后计算视图之间使用的空间。在那之后,我只是使用视觉语言格式设置约束:
- (void)updateViewConstraints {
[super updateViewConstraints];
[self.view removeConstraints:self.view.constraints];
NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(cancelButton, nextButton, middleButton);
float distance=(self.view.bounds.size.width-cancelButton.intrinsicContentSize.width-nextButton.intrinsicContentSize.width-middleButton.intrinsicContentSize.width-20-20)/ ([viewsDictionary count]-1); // 2 times 20 counts for the left & rigth margins
NSNumber *distancies=[NSNumber numberWithFloat:distance];
// NSLog(@"Distancies: %@", distancies);
//
// NSLog(@"View Width: %f", self.view.bounds.size.width);
// NSLog(@"Cancel Width: %f", cancelButton.intrinsicContentSize.width);
// NSLog(@"Middle Width: %f", middleButton.intrinsicContentSize.width);
// NSLog(@"Next Width: %f", nextButton.intrinsicContentSize.width);
NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|-[cancelButton]-dis-[middleButton]-dis-[nextButton]-|"
options:NSLayoutFormatAlignAllBaseline
metrics:@{@"dis":distancies}
views:viewsDictionary];
[self.view addConstraints:constraints];
constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[nextButton]-|"
options:0
metrics:nil
views:viewsDictionary];
[self.view addConstraints:constraints];
}
这种方法的好处是你只需要做很少的数学运算。我并不是说这是完美的解决方案,但我为我试图实现的布局工作。
我希望这能有所帮助。
你可以创建一个tableView并使isScrollEnabled = false。
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。