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

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")
    }

其他回答

在我的情况下,我创建了一个NSDictionary称为appSettings并添加所有需要的键。对于这种情况,解决方案是:

if let dict = NSBundle.mainBundle().objectForInfoDictionaryKey("appSettings") {
  if let configAppToken = dict["myKeyInsideAppSettings"] as? String {

  }
}

我一直在使用Swift 3.0,并希望为更新的语法贡献一个答案。此外,可能更重要的是,我使用PropertyListSerialization对象来做繁重的工作,这比仅仅使用NSDictionary灵活得多,因为它允许数组作为plist的根类型。

下面是我正在使用的plist的截图。这有点复杂,以便显示可用的功率,但这将适用于任何允许的plist类型组合。

正如你所看到的,我正在使用字符串数组:字符串字典来存储网站名称及其对应的URL列表。

如上所述,我使用PropertyListSerialization对象来为我做繁重的工作。此外,Swift 3.0变得更加“Swifty”,所以所有的对象名称都失去了“NS”前缀。

let path = Bundle.main().pathForResource("DefaultSiteList", ofType: "plist")!
let url = URL(fileURLWithPath: path)
let data = try! Data(contentsOf: url)
let plist = try! PropertyListSerialization.propertyList(from: data, options: .mutableContainers, format: nil)

在上面的代码运行后,plist的类型将是Array<AnyObject>,但我们知道它的实际类型,所以我们可以将它强制转换为正确的类型:

let dictArray = plist as! [[String:String]]
// [[String:String]] is equivalent to Array< Dictionary<String, String> >

现在我们可以以自然的方式访问Array of String:String dictionary的各种属性。希望将它们转换为实际的强类型结构体或类;)

print(dictArray[0]["Name"])

如果我想将.plist转换为Swift字典,这是我所做的:

if let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist") {
  if let dict = NSDictionary(contentsOfFile: path) as? Dictionary<String, AnyObject> {
    // use swift dictionary as normal
  }
}

为Swift 2.0编辑:

if let path = NSBundle.mainBundle().pathForResource("Config", ofType: "plist"), dict = NSDictionary(contentsOfFile: path) as? [String: AnyObject] {
    // use swift dictionary as normal
}

为Swift 3.0编辑:

if let path = Bundle.main.path(forResource: "Config", ofType: "plist"), let dict = NSDictionary(contentsOfFile: path) as? [String: AnyObject] {
        // use swift dictionary as normal
}

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)

Swift -读写plist和文本文件....

override func viewDidLoad() {
    super.viewDidLoad()

    let fileManager = (NSFileManager .defaultManager())
    let directorys : [String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory,NSSearchPathDomainMask.AllDomainsMask, true) as? [String]

    if (directorys != nil){
        let directories:[String] = directorys!;
        let dictionary = directories[0]; //documents directory


        //  Create and insert the data into the Plist file  ....
        let plistfile = "myPlist.plist"
        var myDictionary: NSMutableDictionary = ["Content": "This is a sample Plist file ........."]
        let plistpath = dictionary.stringByAppendingPathComponent(plistfile);

        if !fileManager .fileExistsAtPath(plistpath){//writing Plist file
            myDictionary.writeToFile(plistpath, atomically: false)
        }
        else{            //Reading Plist file
            println("Plist file found")

            let resultDictionary = NSMutableDictionary(contentsOfFile: plistpath)
            println(resultDictionary?.description)
        }


        //  Create and insert the data into the Text file  ....
        let textfile = "myText.txt"
        let sampleText = "This is a sample text file ......... "

        let textpath = dictionary.stringByAppendingPathComponent(textfile);
        if !fileManager .fileExistsAtPath(textpath){//writing text file
            sampleText.writeToFile(textpath, atomically: false, encoding: NSUTF8StringEncoding, error: nil);
        } else{
            //Reading text file
            let reulttext  = String(contentsOfFile: textpath, encoding: NSUTF8StringEncoding, error: nil)
            println(reulttext)
        }
    }
    else {
        println("directory is empty")
    }
}