85

我一直在网上寻找很多片段，但我仍然找不到我的问题的答案。我的问题是我有一个scrollView（SV），我想以编程方式在scrollView（SV）内添加一个按钮，其父视图的宽度和高度相同，即scrollView（SV），这样当用户旋转设备按钮时，它将具有相同的框架滚动视图（SV）。如何做 NSLayout/NSLayoutConstraint？谢谢

4

11 回答 11

127

如果有人正在寻找一个Swift 解决方案——我会创建一个 Swift扩展，UIView每次你想将一个子视图框架绑定到它的超级视图边界时，它都会为你提供帮助：

斯威夫特 2：

extension UIView {

    /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
    /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
    func bindFrameToSuperviewBounds() {
        guard let superview = self.superview else {
            print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
            return
        }

        self.translatesAutoresizingMaskIntoConstraints = false
        superview.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-0-[subview]-0-|", options: .DirectionLeadingToTrailing, metrics: nil, views: ["subview": self]))
        superview.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-0-[subview]-0-|", options: .DirectionLeadingToTrailing, metrics: nil, views: ["subview": self]))
    }

}

斯威夫特 3：

extension UIView {

    /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
    /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
    func bindFrameToSuperviewBounds() {
        guard let superview = self.superview else {
            print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
            return
        }

        self.translatesAutoresizingMaskIntoConstraints = false
        superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
        superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
    }
}

斯威夫特 4.2：

extension UIView {

    /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
    /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
    func bindFrameToSuperviewBounds() {
        guard let superview = self.superview else {
            print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
            return
        }

        self.translatesAutoresizingMaskIntoConstraints = false
        self.topAnchor.constraint(equalTo: superview.topAnchor, constant: 0).isActive = true
        self.bottomAnchor.constraint(equalTo: superview.bottomAnchor, constant: 0).isActive = true
        self.leadingAnchor.constraint(equalTo: superview.leadingAnchor, constant: 0).isActive = true
        self.trailingAnchor.constraint(equalTo: superview.trailingAnchor, constant: 0).isActive = true

    }
}

然后简单地这样称呼它：

// after adding as a subview, e.g. `view.addSubview(subview)`
subview.bindFrameToSuperviewBounds()
于 2015-09-28T13:45:47.267 回答
69

我不确定这是否是最有效的方法，但它有效..

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.translatesAutoresizingMaskIntoConstraints = NO;
// initialize


[coverForScrolView addSubview:button];

NSLayoutConstraint *width =[NSLayoutConstraint
                                    constraintWithItem:button
                                    attribute:NSLayoutAttributeWidth
                                    relatedBy:0
                                    toItem:coverForScrolView
                                    attribute:NSLayoutAttributeWidth
                                    multiplier:1.0
                                    constant:0];
NSLayoutConstraint *height =[NSLayoutConstraint
                                     constraintWithItem:button
                                     attribute:NSLayoutAttributeHeight
                                     relatedBy:0
                                     toItem:coverForScrolView
                                     attribute:NSLayoutAttributeHeight
                                     multiplier:1.0
                                     constant:0];
NSLayoutConstraint *top = [NSLayoutConstraint
                                   constraintWithItem:button
                                   attribute:NSLayoutAttributeTop
                                   relatedBy:NSLayoutRelationEqual
                                   toItem:coverForScrolView
                                   attribute:NSLayoutAttributeTop
                                   multiplier:1.0f
                                   constant:0.f];
NSLayoutConstraint *leading = [NSLayoutConstraint
                                       constraintWithItem:button
                                       attribute:NSLayoutAttributeLeading
                                       relatedBy:NSLayoutRelationEqual
                                       toItem:coverForScrolView
                                       attribute:NSLayoutAttributeLeading
                                       multiplier:1.0f
                                       constant:0.f];
[coverForScrolView addConstraint:width];
[coverForScrolView addConstraint:height];
[coverForScrolView addConstraint:top];
[coverForScrolView addConstraint:leading];
于 2013-09-13T08:10:04.190 回答
49

此链接可以帮助您，按照说明操作： http ://www.raywenderlich.com/20881/beginning-auto-layout-part-1-of-2

编辑 ：

使用以下代码片段，其中 subview 是您的 subivew。

[subview setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addConstraints:[NSLayoutConstraint
                           constraintsWithVisualFormat:@"H:|-0-[subview]-0-|"
                           options:NSLayoutFormatDirectionLeadingToTrailing
                           metrics:nil
                           views:NSDictionaryOfVariableBindings(subview)]];
[self.view addConstraints:[NSLayoutConstraint
                           constraintsWithVisualFormat:@"V:|-0-[subview]-0-|"
                           options:NSLayoutFormatDirectionLeadingToTrailing
                           metrics:nil
                           views:NSDictionaryOfVariableBindings(subview)]];
于 2013-09-12T08:26:05.327 回答
20

addConstraintUIView和removeConstraint方法将被弃用，因此值得使用“约束创建便利”：

view.topAnchor.constraint(equalTo: superView.topAnchor, constant: 0).isActive = true
view.bottomAnchor.constraint(equalTo: superView.bottomAnchor, constant: 0).isActive = true
view.leadingAnchor.constraint(equalTo: superView.leadingAnchor, constant: 0).isActive = true
view.trailingAnchor.constraint(equalTo: superView.trailingAnchor, constant: 0).isActive = true
于 2017-03-27T09:35:16.320 回答
8

方法 #1：通过 UIView 扩展

这是Swift 3+中一种更实用的方法，它带有一个先决条件而不是 a （它很容易在控制台中消失）。这会将程序员错误报告为失败的构建。print

将此扩展添加到您的项目中：

extension UIView {
    /// Adds constraints to the superview so that this view has same size and position.
    /// Note: This fails the build if the `superview` is `nil` – add it as a subview before calling this.
    func bindEdgesToSuperview() {
        guard let superview = superview else {
            preconditionFailure("`superview` was nil – call `addSubview(view: UIView)` before calling `bindEdgesToSuperview()` to fix this.")
        }
        translatesAutoresizingMaskIntoConstraints = false
        ["H:|-0-[subview]-0-|", "V:|-0-[subview]-0-|"].forEach { visualFormat in
            superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: visualFormat, options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
        }
    }
}

现在简单地这样称呼它：

// after adding as a subview, e.g. `view.addSubview(subview)`
subview.bindEdgesToSuperview()

请注意，上面的方法已经集成到我的HandyUIKit框架中，它还在您的项目中添加了一些更方便的 UI 助手。

方法 #2：使用框架

如果您在项目中经常使用编程约束，那么我建议您查看SnapKit。它使处理约束变得更加容易且不易出错。

按照文档中的安装说明将 SnapKit 包含到您的项目中。然后将其导入Swift 文件的顶部：

import SnapKit

现在您可以通过以下方式实现相同的目标：

subview.snp.makeConstraints { make in
    make.edges.equalToSuperview()
}
于 2016-12-30T09:24:07.733 回答
6

斯威夫特 3：

import UIKit

extension UIView {

    func bindFrameToSuperviewBounds() {
        guard let superview = self.superview else {
            print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
            return
        }

        self.translatesAutoresizingMaskIntoConstraints = false
        superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
        superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
    }

}
于 2016-09-17T16:44:40.870 回答
2

斯威夫特 4使用NSLayoutConstraint：

footerBoardImageView.translatesAutoresizingMaskIntoConstraints = false
let widthConstraint  = NSLayoutConstraint(item: yourview, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: superview, attribute: NSLayoutAttribute.width, multiplier: 1, constant: 0)
let heightConstraint = NSLayoutConstraint(item: yourview, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: superview, attribute: NSLayoutAttribute.height, multiplier: 1, constant: 0)
superview.addConstraints([widthConstraint, heightConstraint])
于 2017-12-06T17:09:05.770 回答
2

我从其他答案中挑选了最好的元素：

extension UIView {
  /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
  /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
  func bindFrameToSuperviewBounds() {
    guard let superview = self.superview else {
      print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
      return
    }

    self.translatesAutoresizingMaskIntoConstraints = false

    NSLayoutConstraint.activate([
      self.topAnchor.constraint(equalTo: superview.topAnchor),
      self.bottomAnchor.constraint(equalTo: superview.bottomAnchor),
      self.leadingAnchor.constraint(equalTo: superview.leadingAnchor),
      self.trailingAnchor.constraint(equalTo: superview.trailingAnchor)
    ])
  }
}

您可以像这样使用它，例如在您的自定义 UIView 中：

let myView = UIView()
myView.backgroundColor = UIColor.red

self.addSubview(myView)
myView.bindFrameToSuperviewBounds()
于 2020-07-16T00:42:37.870 回答
1

作为补充答案，对于那些不反对包含第三方库的人来说，PureLayout库提供了一种方法来做到这一点。安装库后，它就像

myView.autoPinEdgesToSuperviewEdges()

还有其他库也可以根据口味提供类似的功能，例如。砌体，制图。

于 2016-09-13T03:57:19.130 回答
0

作为@Dschee 解决方案的后续，这里是 swift 3.0 语法：（请注意：这不是我的解决方案，我刚刚为 Swift 3.0 修复了它）

extension UIView {

    /// Adds constraints to this `UIView` instances `superview` object to make sure this always has the same size as the superview.
    /// Please note that this has no effect if its `superview` is `nil` – add this `UIView` instance as a subview before calling this.
    func bindFrameToSuperviewBounds() {
        guard let superview = self.superview else {
            print("Error! `superview` was nil – call `addSubview(view: UIView)` before calling `bindFrameToSuperviewBounds()` to fix this.")
            return
        }

        self.translatesAutoresizingMaskIntoConstraints = false
        superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
    superview.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": self]))
}
于 2016-11-18T15:30:16.773 回答
0

我需要完全覆盖superview。其他的在方向变化时不会这样做。所以我写了一个新的——使用任意大小的乘数 20。随意改变你的需要。另请注意，这实际上使子视图比父视图大得多，这可能与要求不同。

extension UIView {
    func coverSuperview() {
        guard let superview = self.superview else {
            assert(false, "Error! `superview` was nil – call `addSubview(_ view: UIView)` before calling `\(#function)` to fix this.")
            return
        }
        self.translatesAutoresizingMaskIntoConstraints = false
        let multiplier = CGFloat(20.0)
        NSLayoutConstraint.activate([
            self.heightAnchor.constraint(equalTo: superview.heightAnchor, multiplier: multiplier),
            self.widthAnchor.constraint(equalTo: superview.widthAnchor, multiplier: multiplier),
            self.centerXAnchor.constraint(equalTo: superview.centerXAnchor),
            self.centerYAnchor.constraint(equalTo: superview.centerYAnchor),
            ])
    }
}
于 2018-01-27T19:19:34.397 回答