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

你可以使用它,我在github https://github.com/DaRkD0G/LoadExtension中创建了一个简单的字典扩展

extension Dictionary {
    /**
        Load a Plist file from the app bundle into a new dictionary

        :param: File name
        :return: Dictionary<String, AnyObject>?
    */
    static func loadPlistFromProject(filename: String) -> Dictionary<String, AnyObject>? {

        if let path = NSBundle.mainBundle().pathForResource("GameParam", ofType: "plist") {
            return NSDictionary(contentsOfFile: path) as? Dictionary<String, AnyObject>
        }
        println("Could not find file: \(filename)")
        return nil
    }
}

你可以用它来计算负载

/**
  Example function for load Files Plist

  :param: Name File Plist
*/
func loadPlist(filename: String) -> ExampleClass? {
    if let dictionary = Dictionary<String, AnyObject>.loadPlistFromProject(filename) {
        let stringValue = (dictionary["name"] as NSString)
        let intergerValue = (dictionary["score"] as NSString).integerValue
        let doubleValue = (dictionary["transition"] as NSString).doubleValue

        return ExampleClass(stringValue: stringValue, intergerValue: intergerValue, doubleValue: doubleValue)
    }
    return nil
}

其他回答

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")

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

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。

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

我使用swift字典,但在我的文件管理器类中转换它们和nsdictionary,如下所示:

    func writePlist(fileName:String, myDict:Dictionary<String, AnyObject>){
        let docsDir:String = dirPaths[0] as String
        let docPath = docsDir + "/" + fileName
        let thisDict = myDict as NSDictionary
        if(thisDict.writeToFile(docPath, atomically: true)){
            NSLog("success")
        } else {
            NSLog("failure")
        }

    }
    func getPlist(fileName:String)->Dictionary<String, AnyObject>{
        let docsDir:String = dirPaths[0] as String
        let docPath = docsDir + "/" + fileName
        let thisDict = NSDictionary(contentsOfFile: docPath)
        return thisDict! as! Dictionary<String, AnyObject>
    }

这似乎是最不麻烦的读写方式,但让我的其余代码保持尽可能快。