使用Swift实现iOS App中解析XML格式数据的教程

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)

示例：

这里介绍基本的xml数据解析并打印出来.

1.准备xml数据
打开记事本,写下:

<?xml version="1.0" encoding="utf-8" ?>
<students>
  <student id="001">
      <name>Bill Gates</name>
      <age>15</age>
  </student>
  <student id="002">
      <name>Tim Cook</name>
      <age>18</age>
  </student>
</students>

保存命名为data.xml.

2.解析xml
在Xcode中新建一个项目,把data.xml导入新建的工程中,直接拖进去好了.在ViewController.swift里写下如下代码:

class ViewController: UIViewController,NSXMLParserDelegate{

    override func viewDidLoad() {

        super.viewDidLoad()

        let parser = NSXMLParser(contentsOfURL: NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("data", ofType: "xml")!))

        //1

        parser!.delegate = self

        parser!.parse()

    }

    var currentNodeName:String!

    func parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String]) {

        currentNodeName = elementName

        if elementName == "student"{

            if let id = attributeDict["id"]{

            print("id:\(id)")

            }

        }

    }
    func parser(parser: NSXMLParser, foundCharacters string: String) {

        //2

        let str = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())

        if str != "" {

            print("\(currentNodeName):\(str)")

        }

    }
    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}

代码注释:
1.使用NSXMLParser需要NSXMLParserDelegate代理
2.去除打印如<student>的标签,如果直接写成

func parser(parser: NSXMLParser, foundCharacters string: String) { 

       print("\(string):\(str)")

 }

将会把前面的标签打印出来.

3.代码运行结果

id:001
name:Bill Gates
age:15
id:002
name:Tim Cook
age:18