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
以下是我找到的解决方案:
let levelBlocks = NSDictionary(contentsOfFile: NSBundle.mainBundle().pathForResource("LevelBlocks", ofType: "plist"))
let test: AnyObject = levelBlocks.objectForKey("Level1")
println(test) // Prints the value of test
我将测试类型设置为AnyObject，以关闭关于可能发生的意外推断的警告。
而且，它必须在类方法中完成。
访问并保存已知类型的特定值:
let value = levelBlocks.objectForKey("Level1").objectForKey("amount") as Int
println(toString(value)) // Converts value to String and prints it
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)
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)")
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。
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")
}
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)。
