Fork me on GitHub

R.Swift高效引用资源文件

  • 在iOS中当我们引用一张图片的时候, 我们需要创建一个UIImage对象去引用图片
  • 当我们需要解析json或者plist文件的时候, 通常以Bundle.main的方式去解析
1
2
let oldImage = UIImage(named: "yellow-image")
let jsonData = Bundle.main.path(forResource: "menuList", ofType: "json")
  • 这里得到的oldImagejsonData都是Optional类型, 那么这样就会有一个问题: 如果以上文件名字修改了或者输错了, 那么得到的结果就是空的, 后期处理的时候就可能会程序崩溃或者没有数据
  • 而且类似方法接受的都是字符串对象, 所以即使传入的错误的字符串, 编译程序的时候也不会报错
  • 为了完美的解决上面的问题, 这里介绍一个搞笑引用资源文件的框架R.Swift

什么是R.Swift

  • R.Swift是一款基于Swift平台,针对iOS以及tvOS开发的资源引用框架
  • 它所针对的问题,就是类似于上面提到的一样,避免使用字符串来构造某些资源实例
  • R.Swift能够使用类似语法R.资源类型.资源名称来对某资源进行引用构建
  • R.Swift有着动态生成代码的机制, 它具有以下优点:
    • 代码自动补全:就像输入其他的代码一样,R.Swift支持IDE的代码自动补全
    • 自动检测: 可以自动检测代码是否存在问题, 当我们的资源文件名修改的时候, 这是就会提示资源引用错误

安装和配置R.Swift

安装

  • 使用CocoaPods来对R.Swift进行安装
  • 在你的Podfile文件中添加如下代码, 并在终端运行pod install
1
pod 'R.swift'

配置信息

  1. 如下图所示, 添加一个New Run Script Phase

image

  1. Run Script拖动到Check Pods Manifest.lock的下面, 并添加脚本
1
"$PODS_ROOT/R.swift/rswift" generate "$SRCROOT"

image

  1. Command+B编译项目,在项目代码目录下,会生成一个R.generated.swift 的文件,将它拖如项目中

注意:

  • 不要勾选Copy items if needed选项,因为每次编译都会生成新的R.generated.swift文件,copy的话,旧的R.generated.swift将不会被覆盖
  • 每当我们修改了资源,我们需要Command + B来编译一下项目从而让R.Swift自动进行配置更新
  • 这里是坐着录得一个如何导入和配置R.Swift视频教程
  1. 配置到此完成,这里我们可以看一下R.generated.swift文件的基本内容, 下面我们可以构建自己的项目了
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
struct R: Rswift.Validatable {
fileprivate static let applicationLocale = hostingBundle.preferredLocalizations.first.flatMap(Locale.init) ?? Locale.current
fileprivate static let hostingBundle = Bundle(for: R.Class.self)

static func validate() throws {
try intern.validate()
}


/// This `R.file` struct is generated, and contains static references to 1 files.
struct file {
/// Resource file `menuList.json`.
static let menuListJson = Rswift.FileResource(bundle: R.hostingBundle, name: "menuList", pathExtension: "json")

/// `bundle.url(forResource: "menuList", withExtension: "json")`
static func menuListJson(_: Void = ()) -> Foundation.URL? {
let fileResource = R.file.menuListJson
return fileResource.bundle.url(forResource: fileResource)
}

fileprivate init() {}
}


/// This `R.image` struct is generated, and contains static references to 3 images.
struct image {
/// Image `blueimage`.
static let blueimage = Rswift.ImageResource(bundle: R.hostingBundle, name: "blueimage")
/// Image `computers`.
static let computers = Rswift.ImageResource(bundle: R.hostingBundle, name: "computers")
/// Image `yellow-image`.
static let yellowImage = Rswift.ImageResource(bundle: R.hostingBundle, name: "yellow-image")

/// `UIImage(named: "blueimage", bundle: ..., traitCollection: ...)`
static func blueimage(compatibleWith traitCollection: UIKit.UITraitCollection? = nil) -> UIKit.UIImage? {
return UIKit.UIImage(resource: R.image.blueimage, compatibleWith: traitCollection)
}

/// `UIImage(named: "computers", bundle: ..., traitCollection: ...)`
static func computers(compatibleWith traitCollection: UIKit.UITraitCollection? = nil) -> UIKit.UIImage? {
return UIKit.UIImage(resource: R.image.computers, compatibleWith: traitCollection)
}

/// `UIImage(named: "yellow-image", bundle: ..., traitCollection: ...)`
static func yellowImage(compatibleWith traitCollection: UIKit.UITraitCollection? = nil) -> UIKit.UIImage? {
return UIKit.UIImage(resource: R.image.yellowImage, compatibleWith: traitCollection)
}

fileprivate init() {}
}

/// This `R.nib` struct is generated, and contains static references to 2 nibs.
struct nib {
/// Nib `ImageFontController`.
static let imageFontController = _R.nib._ImageFontController()
/// Nib `NibTableViewCell`.
static let nibTableViewCell = _R.nib._NibTableViewCell()

/// `UINib(name: "ImageFontController", in: bundle)`
static func imageFontController(_: Void = ()) -> UIKit.UINib {
return UIKit.UINib(resource: R.nib.imageFontController)
}

/// `UINib(name: "NibTableViewCell", in: bundle)`
static func nibTableViewCell(_: Void = ()) -> UIKit.UINib {
return UIKit.UINib(resource: R.nib.nibTableViewCell)
}

fileprivate init() {}
}


/// This `R.storyboard` struct is generated, and contains static references to 3 storyboards.
struct storyboard {
/// Storyboard `LaunchScreen`.
static let launchScreen = _R.storyboard.launchScreen()
/// Storyboard `Main`.
static let main = _R.storyboard.main()
/// Storyboard `NibHome`.
static let nibHome = _R.storyboard.nibHome()

/// `UIStoryboard(name: "LaunchScreen", bundle: ...)`
static func launchScreen(_: Void = ()) -> UIKit.UIStoryboard {
return UIKit.UIStoryboard(resource: R.storyboard.launchScreen)
}

/// `UIStoryboard(name: "Main", bundle: ...)`
static func main(_: Void = ()) -> UIKit.UIStoryboard {
return UIKit.UIStoryboard(resource: R.storyboard.main)
}

/// `UIStoryboard(name: "NibHome", bundle: ...)`
static func nibHome(_: Void = ()) -> UIKit.UIStoryboard {
return UIKit.UIStoryboard(resource: R.storyboard.nibHome)
}

fileprivate init() {}
}

fileprivate init() {}
}

R.Swift的使用

Images - 图片

1
2
3
4
5
6
7
//传统方式
let oldImage = UIImage(named: "yellow-image")
oldImageView.image = oldImage

//R.Swift方式
let newImage = R.image.yellowImage()
newImageView.image = newImage

Custom fonts - 字体

这里需要注意的一点是, 字体的引用需要引入一个ttf格式的字体文件, 不然无法编译除类似acmeLight的函数

1
2
3
4
5
//传统方式
let lightFontTitle = UIFont(name: "Acme-Light", size: 22)

//R.Swift方式
let lightFontTitle = R.font.acmeLight(size: 22)

Resource files - 数据文件

1
2
3
4
5
6
7
//传统方式
let jsonData = Bundle.main.path(forResource: "menuList", ofType: "json")
let jsonUrl1 = Bundle.main.url(forResource: "menuList", withExtension: "json")

//R.Swift方式
let jsonData2 = R.file.menuListJson.path()
let newUrl = R.file.menuListJson()

Storyboards

1
2
3
4
5
6
7
8
9
10
11
12
13
14
//传统方式
let nibVC1 = UIStoryboard(name: "NibHome", bundle: nil).instantiateInitialViewController() ?? UIViewController()

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let initialTabBarController = storyboard.instantiateInitialViewController() as? UITabBarController
let settingsController = storyboard.instantiateViewController(withIdentifier: "settingsController") as? SettingsControllerSettingsController


//R.Swift方式
let nibVC = R.storyboard.nibHome().instantiateInitialViewController() ?? UIViewController()

let storyboard = R.storyboard.main()
let initialTabBarController = R.storyboard.main.initialViewController()
let settingsController = R.storyboard.main.settingsController()

Nibs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
//传统方式
let nameOfNib = "CustomView"
let customViewNib = UINib(nibName: "CustomView", bundle: nil)
let rootViews = customViewNib.instantiate(withOwner: nil, options: nil)
let customView = rootViews[0] as? CustomView

let viewControllerWithNib = CustomViewController(nibName: "CustomView", bundle: nil)


//R.Swift方式
let nameOfNib = R.nib.customView.name
let customViewNib = R.nib.customView()
let rootViews = R.nib.customView.instantiate(withOwner: nil)
let customView = R.nib.customView.firstView(owner: nil)

let viewControllerWithNib = CustomViewController(nib: R.nib.customView)

Reusable table view cells - cell复用

这里是UITableViewCell的注册和使用为例, UICollectionViewCell亦同理

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
//传统方式
let cellNib = UINib(nibName: "NibTableViewCell", bundle: nil)
tableView.register(cellNib, forCellReuseIdentifier: "NibTableViewCell")

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "NibTableViewCell", for: indexPath)
cell?.leftLabel.text = dataArr[indexPath.row]
return cell ?? UITableViewCell()
}


//R.Swift方式
tableView.register(R.nib.nibTableViewCell(), forCellReuseIdentifier: R.nib.nibTableViewCell.name)

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: R.nib.nibTableViewCell.name, for: indexPath) as? NibTableViewCell
cell?.leftLabel.text = dataArr[indexPath.row]
return cell ?? UITableViewCell()
}

更多关于R.Swift的使用可参考官方文档Examples.md


-------------本文结束感谢您的阅读-------------
欢迎您扫一扫下面的微信公众号,订阅我的博客!
TitanKing wechat
坚持原创技术分享,您的支持将鼓励我继续创作!
分享到:
0%