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)
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解析文件，返回的是一次解析的结果
NSXMLParser.parse() -> Bool
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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])
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监听解析节点的内容
NSXMLParserDelegate.parser(parser: NSXMLParser, foundCharacters string: String)
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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.
    }
}
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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)")
 }
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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