(Swift)闭包作为方法参数

<img src="http://snapkit.io/images/banner.jpg" alt="" /> SnapKit is a DSL to make Auto Layout easy on both iOS and OS X. [](https://travis-ci.org/SnapKit/SnapKit) [](https://github.com/SnapKit/SnapKit) [](https://cocoapods.org/pods/SnapKit) [](https://github.com/Carthage/Carthage) #### ⚠️ **To use with Swift 4.x please ensure you are using >= 4.0.0** ⚠️ #### ⚠️ **To use with Swift 5.x please ensure you are using >= 5.0.0** ⚠️ ## Contents - [Requirements](#requirements) - [Migration Guides](#migration-guides) - [Communication](#communication) - [Installation](#installation) - [Usage](#usage) - [Credits](#credits) - [License](#license) ## Requirements - iOS 10.0+ / Mac OS X 10.12+ / tvOS 10.0+ - Xcode 10.0+ - Swift 4.0+ ## Communication - If you **need help**, use [Stack Overflow](http://stackoverflow.com/questions/tagged/snapkit). (Tag 'snapkit') - If you'd like to **ask a general question**, use [Stack Overflow](http://stackoverflow.com/questions/tagged/snapkit). - If you **found a bug**, open an issue. - If you **have a feature request**, open an issue. - If you **want to contribute**, submit a pull request. ## Installation ### CocoaPods [CocoaPods](http://cocoapods.org) is a dependency manager for Cocoa projects. You can install it with the following command: ```bash $ gem install cocoapods ``` > CocoaPods 1.1.0+ is required to build SnapKit 4.0.0+. To integrate SnapKit into your Xcode project using CocoaPods, specify it in your `Podfile`: ```ruby source 'https://github.com/CocoaPods/Specs.git' platform :ios, '10.0' use_frameworks! target '<Your Target Name>' do pod 'SnapKit', '~> 5.0.0' end ``` Then, run the following command: ```bash $ pod install ``` ### Carthage [Carthage](https://github.com/Carthage/Carthage) is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks. You can install Carthage with [Homebrew](http://brew.sh/) using the following command: ```bash $ brew update $ brew install carthage ``` To integrate SnapKit into your Xcode project using Carthage, specify it in your `Cartfile`: ```ogdl github "SnapKit/SnapKit" ~> 5.0.0 ``` Run `carthage update` to build the framework and drag the built `SnapKit.framework` into your Xcode project. ### Manually If you prefer not to use either of the aforementioned dependency managers, you can integrate SnapKit into your project manually. --- ## Usage ### Quick Start ```swift import SnapKit class MyViewController: UIViewController { lazy var box = UIView() override func viewDidLoad() { super.viewDidLoad() self.view.addSubview(box) box.snp.makeConstraints { (make) -> Void in make.width.height.equalTo(50) make.center.equalTo(self.view) } } } ``` ### Playground You can try SnapKit in Playground. **Note:** > To try SnapKit in playground, open `SnapKit.xcworkspace` and build SnapKit.framework for any simulator first. ### Resources - [Documentation](http://snapkit.io/docs/) - [F.A.Q.](http://snapkit.io/faq/) ## Credits - Robert Payne ([@robertjpayne](https://twitter.com/robertjpayne)) - Many other contributors ## License SnapKit is released under the MIT license. See LICENSE for details.