WTAutoLayoutExtensions 1.0.2

您想在 Podfile 中添加如下代码来添加 pod 'WTAutoLayoutExtensions', '~> 1.0'

target 'MyApp' do
  pod 'WTAutoLayoutExtensions', '~> 1.0'
end

然后，在第个终端中运行 pod install 或从 CocoaPods.app 运行。

或者，为了测试运行，运行以下命令

pod try WTAutoLayoutExtensions

WTAutoLayoutExtensions 1.0.2

由
Wagner Truppel

WTAutoLayoutExtensions

什么是

WTAutoLayoutExtensions 为 UIView 和 UILayoutGuide 增加了扩展，使得使用布局指南、布局锚点以及自动布局的其余部分更加简单和自然，具有一致的 API 和极少的代码。

以下是添加到 UIView 的完整 API 扩展集。有关详细信息，请参阅源文件中的完整文档。

public extension UIView {

    /// Apple's standard distance between most UI elements, as a static property. No magic numbers!
    static public let standardValue: CGFloat

    /// Sets up commonly used priorities for the view's content compression resistance.
    public func setupCommonContentCompressionResistancePriorities()

    /// Sets up commonly used priorities for the view's content hugging property.
    public func setupCommonContentHuggingPriorities()

    /// Pins a view's edges to its superview's edges.
    public func wtPinToSuperview(with edgeInsets: UIEdgeInsets,
                                 useMargin: Bool,
                                 useSuperviewMargin: Bool,
                                 priority: UILayoutPriority,
                                 active: Bool)

    /// Centers a view in its superview.
    public func wtCenterInSuperview(useMargin: Bool,
                                    useSuperviewMargin: Bool,
                                    priority: UILayoutPriority,
                                    active: Bool)

    /// Creates layout constraints for the **width** or the **height** of a view
    /// or layout guide.
    public static func wtConstraint(on attribute: NSLayoutAttribute,
                                    _ item: WTAutoLayoutExtensionsAware,
                                    _ relation: NSLayoutRelation,
                                    _ constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints for the **aspect ratio** (width divided by height)
    /// of a view or layout guide.
    public static func wtAspectRatioConstraint(on item: WTAutoLayoutExtensionsAware,
                                               _ relation: NSLayoutRelation,
                                               _ ratio: CGFloat,
                                               priority: UILayoutPriority,
                                               active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints between the **widths** or **heights** of two views,
    /// two layout guides, or a view and a layout guide (in either order).
    public static func wtConstraint(on attribute: NSLayoutAttribute,
                                    _ item1: WTAutoLayoutExtensionsAware,
                                    _ relation: NSLayoutRelation,
                                    _ item2: WTAutoLayoutExtensionsAware,
                                    times multiplier: CGFloat,
                                    plus constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints to align two views, two layout guides, or a view
    /// and a layout guide (in either order) on **compatible positional attributes**.
    public static func wtConstraint(_ item1: WTAutoLayoutExtensionsAware,
                                    _ attribute1: NSLayoutAttribute,
                                    _ relation: NSLayoutRelation,
                                    _ item2: WTAutoLayoutExtensionsAware,
                                    _ attribute2: NSLayoutAttribute,
                                    plus constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints to arrange two views, two layout guides, or a view
    /// and a layout guide (in either order) along the **horizontal** direction.
    public static func wtConstraint(_ item1: WTAutoLayoutExtensionsAware,
                                    leading item2: WTAutoLayoutExtensionsAware,
                                    offset relation: NSLayoutRelation,
                                    _ constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints to arrange two views, two layout guides, or a view
    /// and a layout guide (in either order) along the **horizontal** direction.
    public static func wtConstraint(_ item1: WTAutoLayoutExtensionsAware,
                                    trailing item2: WTAutoLayoutExtensionsAware,
                                    offset relation: NSLayoutRelation,
                                    _ constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints to arrange two views, two layout guides, or a view
    /// and a layout guide (in either order) along the **vertical** direction.
    public static func wtConstraint(_ item1: WTAutoLayoutExtensionsAware,
                                    above item2: WTAutoLayoutExtensionsAware,
                                    offset relation: NSLayoutRelation,
                                    _ constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// Creates layout constraints to arrange two views, two layout guides, or a view
    /// and a layout guide (in either order) along the **vertical** direction.
    public static func wtConstraint(_ item1: WTAutoLayoutExtensionsAware,
                                    below item2: WTAutoLayoutExtensionsAware,
                                    offset relation: NSLayoutRelation,
                                    _ constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// For the rare situation where the API defined above isn't sufficient, this
    /// method lets you directly create a constraint on a dimensional **anchor**.
    public static func wtConstraint(on dimensionalAnchor: NSLayoutDimension,
                                    _ relation: NSLayoutRelation,
                                    constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// For the rare situation where the API defined above isn't sufficient, this
    /// method lets you directly create a constraint on a pair of dimensional **anchors**.
    public static func wtConstraint(_ dimensionalAnchor1: NSLayoutDimension,
                                    _ relation: NSLayoutRelation,
                                    _ dimensionalAnchor2: NSLayoutDimension,
                                    times multiplier: CGFloat,
                                    plus constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// For the rare situation where the API defined above isn't sufficient, this
    /// method lets you directly create a constraint on a pair of positional **anchors**.
    public static func wtConstraint<T>(_ positionalAnchor1: NSLayoutAnchor<T>,
                                    _ relation: NSLayoutRelation,
                                    _ positionalAnchor2: NSLayoutAnchor<T>,
                                    plus constant: CGFloat,
                                    priority: UILayoutPriority,
                                    active: Bool) -> NSLayoutConstraint

    /// This method causes the layout guides of the recipient to be displayed as
    /// rectangles of "marching ants" with the given color. Useful for debugging.
    /// See acknowledgement note below.
    public func showLayoutGuides(color: UIColor)

}

示例

上面列出的完整 API 可能看起来既不简单也不自然，但以下是一些使用示例。这些示例直接取自附带的示例项目。

        // unbroken leading-to-trailing chain
        UIView.wtConstraint(view, .leadingMargin, .equal, leftGuide, .leading)
        UIView.wtConstraint(leftGuide, .trailing, .equal, u1, .leading)
        UIView.wtConstraint(u1, .trailing, .equal, middleGuide, .leading)
        UIView.wtConstraint(middleGuide, .trailing, .equal, u2, .leading)
        UIView.wtConstraint(u2, .trailing, .equal, rightGuide, .leading)
        UIView.wtConstraint(rightGuide, .trailing, .equal, view, .trailingMargin)

        // equal horizontal spaces
        UIView.wtConstraint(on: .width, middleGuide, .equal, leftGuide)
        UIView.wtConstraint(on: .width, middleGuide, .equal, rightGuide)

        // set aspect ratios
        UIView.wtAspectRatioConstraint(on: u1, .equal, 1)
        UIView.wtAspectRatioConstraint(on: u2, .equal, 2)

        // set heights
        UIView.wtConstraint(on: .height, u1, .equal, 100)
        UIView.wtConstraint(on: .height, u1, .equal, u2, times: 1.5, plus: 20)

        // arrange vertically
        UIView.wtConstraint(u1, .top, .equal, view, .topMargin, plus: 50)
        UIView.wtConstraint(u1, above: u2, offset: .equal, 100)

        // set layout guide heights
        UIView.wtConstraint(leftGuide, .top, .equal, u1, .top)
        UIView.wtConstraint(leftGuide, .bottom, .equal, u2, .bottom)
        //
        UIView.wtConstraint(middleGuide, .top, .equal, u1, .top)
        UIView.wtConstraint(middleGuide, .bottom, .equal, u2, .bottom)
        //
        UIView.wtConstraint(rightGuide, .top, .equal, u1, .top)
        UIView.wtConstraint(rightGuide, .bottom, .equal, u2, .bottom)

        // set size
        UIView.wtConstraint(on: .width,  u3, .equal, 80)
        UIView.wtConstraint(on: .height, u3, .equal, 80)

        // center it
        u3.wtCenterInSuperview()

如您所见，我希望您会同意，调用站的调用方法读起来非常自然。API 非常一致

所有返回约束的方法都是 UIView 的 静态 方法。
如果愿意，可以忽略返回值而无需使用 _ =。
用于约束单个项目或两个项目的单个公共属性的方法定名为 wtConstraint(on ...)（唯一的例外是长宽比），而所讨论的项目或属性则作为第一个参数出现。
那些约束两个项目的不同属性则不带 on 命名。
使用带有 wt 前缀命名方法是有意为之，以防止将来向 UIView 添加类似命名的添加方法，并且 Xcode 的自动 Completion 会在您键入 wtc 后将列表缩小得相当好。
一些方法支持乘数和/或常量，并且当它们这样做时，它们在方法签名中的位置非常自然，例如：UIView.wtConstraint(on: .height, u1, .equal, u2, times: 1.5, plus: 20)
方法也支持优先级和活动/非活动状态。
所有默认值都是合理的。
您不必强使用 .equal。您也可以轻松地写入类似 UIView.wtConstraint(on: .width, u1, .greaterThanOrEqual, u2, times: 1.5, plus: 20) 或 UIView.wtConstraint(on: .width, u1, .lessThanOrEqual, u2) 的内容。

要运行示例项目，请克隆代码库，然后首先从Examples目录中运行pod install。

变更日志

WTAutoLayoutExtensions的变更列在这里：https://github.com/wltrup/iOS-Swift-WTAutoLayoutExtensions/blob/master/CHANGELOG.md。

需求

WTAutoLayoutExtensions仅支持iOS 9.0及更高版本。

安装

WTAutoLayoutExtensions可通过CocoaPods获取。要安装它，只需在Podfile中添加以下行：

pod "WTAutoLayoutExtensions"

作者

Wagner Truppel，[email protected]

许可证

WTAutoLayoutExtensions在MIT许可下可用。有关更多信息，请参阅LICENSE文件。

致谢

函数showLayoutGuides(color:)及其支持代码是基于Jack Cox的工作和改编制作而成。查看他的博客文章和GitHub代码库。