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
你仍然可以在Swift中使用nsdictionary:
Swift 4
var nsDictionary: NSDictionary?
if let path = Bundle.main.path(forResource: "Config", ofType: "plist") {
nsDictionary = NSDictionary(contentsOfFile: path)
}
Swift 3+
if let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
let myDict = NSDictionary(contentsOfFile: path){
// Use your myDict here
}
以及旧版本的Swift
var myDict: NSDictionary?
if let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist") {
myDict = NSDictionary(contentsOfFile: path)
}
if let dict = myDict {
// Use your dict here
}
NSClasses仍然可用，完全可以在Swift中使用。我想他们可能很快就会把重点转移到swift上，但是目前swift api并没有核心NSClasses的所有功能。
其他回答
在swift 3.0从Plist读取。
func readPropertyList() {
var propertyListFormat = PropertyListSerialization.PropertyListFormat.xml //Format of the Property List.
var plistData: [String: AnyObject] = [:] //Our data
let plistPath: String? = Bundle.main.path(forResource: "data", ofType: "plist")! //the path of the data
let plistXML = FileManager.default.contents(atPath: plistPath!)!
do {//convert the data to a dictionary and handle errors.
plistData = try PropertyListSerialization.propertyList(from: plistXML, options: .mutableContainersAndLeaves, format: &propertyListFormat) as! [String:AnyObject]
} catch {
print("Error reading plist: \(error), format: \(propertyListFormat)")
}
}
阅读更多 如何在swift中使用属性列表(. plist)。
斯威夫特3.0
if let path = Bundle.main.path(forResource: "config", ofType: "plist") {
let dict = NSDictionary(contentsOfFile: path)
// use dictionary
}
在我看来，这是最简单的方法。
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)
步骤1:简单和最快的方法来解析plist在swift 3+
extension Bundle {
func parsePlist(ofName name: String) -> [String: AnyObject]? {
// check if plist data available
guard let plistURL = Bundle.main.url(forResource: name, withExtension: "plist"),
let data = try? Data(contentsOf: plistURL)
else {
return nil
}
// parse plist into [String: Anyobject]
guard let plistDictionary = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil) as? [String: AnyObject] else {
return nil
}
return plistDictionary
}
}
第二步:使用方法:
Bundle().parsePlist(ofName: "Your-Plist-Name")
你仍然可以在Swift中使用nsdictionary:
Swift 4
var nsDictionary: NSDictionary?
if let path = Bundle.main.path(forResource: "Config", ofType: "plist") {
nsDictionary = NSDictionary(contentsOfFile: path)
}
Swift 3+
if let path = Bundle.main.path(forResource: "Config", ofType: "plist"),
let myDict = NSDictionary(contentsOfFile: path){
// Use your myDict here
}
以及旧版本的Swift
var myDict: NSDictionary?
if let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist") {
myDict = NSDictionary(contentsOfFile: path)
}
if let dict = myDict {
// Use your dict here
}
NSClasses仍然可用，完全可以在Swift中使用。我想他们可能很快就会把重点转移到swift上，但是目前swift api并没有核心NSClasses的所有功能。
