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
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)
下面是一个基于@connor的回答的简短版本
guard let path = Bundle.main.path(forResource: "GoogleService-Info", ofType: "plist"),
let myDict = NSDictionary(contentsOfFile: path) else {
return nil
}
let value = dict.value(forKey: "CLIENT_ID") as! String?
因为这个答案还没有在这里，只是想指出，你也可以使用infoDictionary属性来获取信息plist作为字典，Bundle.main.infoDictionary。
比如bundle。main。如果您只对info plist中的特定项感兴趣，则可以使用kCFBundleNameKey作为String)。
// Swift 4
// Getting info plist as a dictionary
let dictionary = Bundle.main.infoDictionary
// Getting the app display name from the info plist
Bundle.main.infoDictionary?[kCFBundleNameKey as String]
// Getting the app display name from the info plist (another way)
Bundle.main.object(forInfoDictionaryKey: kCFBundleNameKey as String)
通过尼克的回答转换成一个方便的扩展:
extension Dictionary {
static func contentsOf(path: URL) -> Dictionary<String, AnyObject> {
let data = try! Data(contentsOf: path)
let plist = try! PropertyListSerialization.propertyList(from: data, options: .mutableContainers, format: nil)
return plist as! [String: AnyObject]
}
}
用法:
let path = Bundle.main.path(forResource: "plistName", ofType: "plist")!
let url = URL(fileURLWithPath: path)
let dict = Dictionary<String, AnyObject>.contentsOf(path: url)
我敢打赌，它也可以为数组创建类似的扩展
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。
