11.Swift XML解析

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XML数据解析

在IOS中，提供了一套解析XML数据的API。其实也很简单，就是NSXMLParser和NSXMLParserDelegate。

可以直接指定到XML的URL去实例化NSXMLParser
public convenience init?(contentsOfURL url: NSURL)

解析文件，返回的是一次解析的结果
NSXMLParser.parse() -> Bool

监听解析节点的属性
NSXMLParserDelegate.parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String])

监听解析节点的内容
NSXMLParserDelegate.parser(parser: NSXMLParser, foundCharacters string: String)

待解析的XML文件：

<data>    <code value="1.0">        <version>1.0.1</version>    </code>    <response>        <info>Save you from anything</info>    </response></data>

ViewController.swift

class ViewController: UIViewController,NSXMLParserDelegate {    var currentNodeName:String!    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.        // 实例化NSXMLParser        let parse:NSXMLParser = NSXMLParser(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("data", ofType: "xml")!))!        parse.delegate = self        // 开始解析        parse.parse()    }    // 监听解析节点的属性    func parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String]){        // 保存当前的解析到的节点名称        self.currentNodeName = elementName        if(elementName == "code"){            // 获取code节点下 value属性的内容            if let value = attributeDict["value"]{                NSLog("value: \(value)")            }        }    }    // 监听解析节点的内容    func parser(parser: NSXMLParser, foundCharacters string: String) {        var content = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())        if(content != "" && self.currentNodeName == "info"){            NSLog("\(content)")        }    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }}

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XML解析选择题

这里再介绍一个关于NSXMLParserDelegate的API。

解析成功，并且解析结束时
NSXMLParserDelegate.parserDidEndDocument(parser: NSXMLParser)

questions.xml

<questions>    <question text="1+1=?" right="C">        <answer text="0" tag="A"></answer>        <answer text="1" tag="B"></answer>        <answer text="2" tag="C"></answer>        <answer text="3" tag="D"></answer>    </question></questions>

Question.swift

class Question: NSObject {    var question:String!    var right:String!    var answerA:String!    var answerB:String!    var answerC:String!    var answerD:String!}

Main.storyboard

ViewController.swift

class ViewController: UIViewController,NSXMLParserDelegate {    @IBOutlet weak var question: UILabel!    @IBOutlet weak var answerA: UILabel!    @IBOutlet weak var answerB: UILabel!    @IBOutlet weak var answerC: UILabel!    @IBOutlet weak var answerD: UILabel!    @IBOutlet weak var inputTV: UITextField!    @IBOutlet weak var hint: UILabel!    var parser:NSXMLParser!    // 用于保存全部题目    var questions:Array<Question> = []    // 用于保存当前解析到的题目    var currentQuestion:Question!    // 用于保存当前显示的题目    var currentShowQuestion:Question!    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.        // 实例化NSXMLParser        self.parser = NSXMLParser(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("questions", ofType: "xml")!))        self.parser.delegate = self        // 开始解析        self.parser.parse()    }    // 监听解析节点的属性    func parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String]) {        switch elementName{            case "question":                // 保存当前到的题目                self.currentQuestion = Question()                // 读取question节点下的 text属性值                self.currentQuestion.question = attributeDict["text"]! as String                // 读取question节点下的 right属性值                self.currentQuestion.right = attributeDict["right"]! as String                self.questions.append(self.currentQuestion)                break            case "answer":                // 读取question节点下的 tag属性值                let tag = attributeDict["tag"]! as String                // 读取question节点下的 text属性值                let text = attributeDict["text"]! as String                // 设置当前到的题目的全部答案内容                switch tag{                    case "A":                        self.currentQuestion.answerA = "\(tag)：\(text)"                        break                    case "B":                        self.currentQuestion.answerB = "\(tag)：\(text)"                        break                    case "C":                        self.currentQuestion.answerC = "\(tag)：\(text)"                        break                    case "D":                        self.currentQuestion.answerD = "\(tag)：\(text)"                        break                    default :                        break                }                break            default :                break        }    }    // 监听解析成功并且结束时    func parserDidEndDocument(parser: NSXMLParser) {        self.currentShowQuestion = self.questions[0]        self.question.text = self.currentShowQuestion.question        self.answerA.text = self.currentShowQuestion.answerA        self.answerB.text = self.currentShowQuestion.answerB        self.answerC.text = self.currentShowQuestion.answerC        self.answerD.text = self.currentShowQuestion.answerD    }    // 提交答案监听    @IBAction func submitOnClicked(sender: AnyObject) {        if let t:String = self.inputTV.text{            let result = t.uppercaseString            if(result == self.currentShowQuestion.right){                self.hint.text = "正确"            }else if (result == ""){                self.hint.text = "输入不合法"            }else {                self.hint.text = "不正确"            }        }else{            self.hint.text = "输入不合法"        }    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }}