12.Swift JSON 和 PList

12.Swift JSON 和 PList

解析PList

PList文件的Root节点只能是Array或者Dictionary类型。IOS对PList的解析是十分简洁、方便的。由于Root节点只能是Array或者Dictionary类型，所以可以直接用NSArray或者NSDictionary的构造方法就能完成解析。

在NSArray的扩展构造方法中能找到一个便利构造方法
public convenience init?(contentsOfURL url: NSURL)

在NSDictionary的扩展构造方法中能找到一个便利构造方法
public convenience init?(contentsOfURL url: NSURL)

待解析的dictPList.plist

待解析的arrayPList.plist

ViewController.swift

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        // 解析Root为Array的PList
        let arrayPList:NSArray = NSArray(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("arrayPList", ofType: "plist")!))!
        // 解析Root为Dictionary的PList
        let dictPList:NSDictionary = NSDictionary(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("dictPList", ofType: "plist")!))!
        NSLog("\(arrayPList)")
        NSLog("\(dictPList)")
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

如果要生成PList文件的话，同样的办法，将NSArray或者NSDictionary传入NSData的构造方法中，最后调用NSData的writeToFile(path: String, atomically useAuxiliaryFile: Bool) -> Bool。

NSJSONSerialization

IOS提供的NSJSONSerialization，可用于将普通数据转换为JSON格式的NSData、解析JSON文件。当数据通过NSJSONSerialization转换为JSON格式的NSData时，NSData又自带了writeToFile(path: String, atomically useAuxiliaryFile: Bool) -> Bool将自身保存为文件；解析JSON的话，需要NSJSONSerialization的JSONObjectWithData(data: NSData, options opt: NSJSONReadingOptions) throws -> AnyObject方法，将.json文件转换为AnyObject类型，再通过AnyObject的objectForKey(aKey: AnyObject) -> AnyObject?去获取其中的内容。

解析JSON
NSJSONSerialization.JSONObjectWithData(data: NSData, options opt: NSJSONReadingOptions) throws -> AnyObject

生成JSON格式的NSData
NSJSONSerialization.JSONObjectWithData(data: NSData, options opt: NSJSONReadingOptions) throws -> AnyObject

mjson.json

{"name":"CaMnter","sign":"Save you from anything"}

ViewController.swift

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.parseJSON()
        self.exportJSON()
    }

    // 解析JSON文件，生成JSONObject
    func parseJSON(){
        do {
            // JSONObjectWithData解析JSON文件
            let json:AnyObject? = try NSJSONSerialization.JSONObjectWithData(NSData(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("mjson", ofType: "json")!))!, options: NSJSONReadingOptions.AllowFragments)
            if let name: AnyObject = json?.objectForKey("name"){
                NSLog("\(name)")
            }
            if let sign: AnyObject = json?.objectForKey("sign"){
                NSLog("\(sign)")
            }
        }catch let error as NSError {
            NSLog("\(error.localizedDescription)")
        }
    }

    // NSData生成JSONObject
    func exportJSON(){
        let dict = ["name":"CaMnter","sign":"Save you from anything"]
        do{
            // dataWithJSONObject生成JSON格式的NSData
            let jsonData:NSData! = try NSJSONSerialization.dataWithJSONObject(dict, options: NSJSONWritingOptions.PrettyPrinted)
            let jsonString:NSString = NSString(data: jsonData, encoding: NSUTF8StringEncoding)!
            NSLog("\(jsonString)")
        }catch let error as NSError {
            NSLog("\(error.localizedDescription)")
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}