我在玩苹果的新Swift编程语言,遇到了一些问题…

目前我试图读取一个plist文件,在Objective-C中,我会做以下工作来获取内容作为NSDictionary:

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"Config" ofType:@"plist"];
NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:filePath];

我如何得到一个plist作为一个字典在Swift?

我假设我可以得到路径到plist:

let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist")

当这工作(如果它是正确的?):我如何获得内容作为一个字典?

还有一个更普遍的问题:

是否可以使用默认的NS*类?我想是的……还是我遗漏了什么?据我所知,默认框架NS*类仍然有效,可以使用吗?


当前回答

最好使用本机字典和数组,因为它们已经针对swift进行了优化。也就是说你可以使用NS。我认为这种情况证明了这一点。下面是你如何实现它:

var path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist")
var dict = NSDictionary(contentsOfFile: path)

到目前为止(在我看来),这是访问plist最简单和最有效的方法,但在未来,我希望苹果将添加更多的功能(比如使用plist)到本地字典中。

其他回答

我已经创建了一个简单的字典初始化器替换NSDictionary(contentsOfFile: path)。只要去掉NS。

extension Dictionary where Key == String, Value == Any {

    public init?(contentsOfFile path: String) {
        let url = URL(fileURLWithPath: path)

        self.init(contentsOfURL: url)
    }

    public init?(contentsOfURL url: URL) {
        guard let data = try? Data(contentsOf: url),
            let dictionary = (try? PropertyListSerialization.propertyList(from: data, options: [], format: nil) as? [String: Any]) ?? nil
            else { return nil }

        self = dictionary
    }

}

你可以这样使用它:

let filePath = Bundle.main.path(forResource: "Preferences", ofType: "plist")!
let preferences = Dictionary(contentsOfFile: filePath)!
UserDefaults.standard.register(defaults: preferences)

这个答案使用Swift本机对象而不是NSDictionary。

斯威夫特3.0

//get the path of the plist file
guard let plistPath = Bundle.main.path(forResource: "level1", ofType: "plist") else { return }
//load the plist as data in memory
guard let plistData = FileManager.default.contents(atPath: plistPath) else { return }
//use the format of a property list (xml)
var format = PropertyListSerialization.PropertyListFormat.xml
//convert the plist data to a Swift Dictionary
guard let  plistDict = try! PropertyListSerialization.propertyList(from: plistData, options: .mutableContainersAndLeaves, format: &format) as? [String : AnyObject] else { return }
//access the values in the dictionary 
if let value = plistDict["aKey"] as? String {
  //do something with your value
  print(value)
}
//you can also use the coalesce operator to handle possible nil values
var myValue = plistDict["aKey"] ?? ""

Swift 4.0 iOS 11.2.6列表解析和代码解析它,基于https://stackoverflow.com/users/3647770/ashok-r上面的答案。

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
  <dict>
    <key>identity</key>
    <string>blah-1</string>
    <key>major</key>
    <string>1</string>
    <key>minor</key>
    <string>1</string>
    <key>uuid</key>
    <string>f45321</string>
    <key>web</key>
    <string>http://web</string>
</dict>
<dict>
    <key>identity</key>
    <string></string>
    <key>major</key>
    <string></string>
    <key>minor</key>
    <string></string>
    <key>uuid</key>
    <string></string>
    <key>web</key>
    <string></string>
  </dict>
</array>
</plist>

do {
   let plistXML = try Data(contentsOf: url)
    var plistData: [[String: AnyObject]] = [[:]]
    var propertyListFormat =  PropertyListSerialization.PropertyListFormat.xml
        do {
            plistData = try PropertyListSerialization.propertyList(from: plistXML, options: .mutableContainersAndLeaves, format: &propertyListFormat) as! [[String:AnyObject]]

        } catch {
            print("Error reading plist: \(error), format: \(propertyListFormat)")
        }
    } catch {
        print("error no upload")
    }

如果你有信息。Plist,然后使用

Bundle.main.infoDictionary

访问plist文件的简单结构(Swift 2.0)

struct Configuration {      
  static let path = NSBundle.mainBundle().pathForResource("Info", ofType: "plist")!
  static let dict = NSDictionary(contentsOfFile: path) as! [String: AnyObject]

  static let someValue = dict["someKey"] as! String
}

用法:

print("someValue = \(Configuration.someValue)")