Android（五十四）：SAX、DOM、XmlReader 解析XML数据

展示

xml文件

• ​​SecondaryBlankApp/Assets/user_info_data.xml​​

<?xml version="1.0" encoding="utf-8" ?>
<userInfos>
  <userInfo id="user_01" class="box-01 box-02">
    <name>Lee</name>
    <age>24</age>
  </userInfo>
  <userInfo id="user_02">
    <name>张三</name>
    <age>18</age>
  </userInfo>
</userInfos>

源码

SAX

// SAX
private string TAG = "DataMessage";
private string _xmlData = "";

var xmlText = FindViewById<TextView>(Resource.Id.xml_text);

var btn01 = FindViewById<Button>(Resource.Id.btn_01);
if (btn01 != null)
    btn01.Click += delegate
    {
        SaxHelper.XmlData = "";
        if (xmlText == null) return;
        // 获取文件资源建立输入流对象
        var stream = Assets?.Open("user_info_data.xml");
        // 创建XML解析处理器
        var saxHelper = new SaxHelper();
        // 得到SAX解析工厂 创建SAX解析器
        var saxParser = SAXParserFactory.NewInstance()?.NewSAXParser();
        // 将xml解析处理器分配给解析器,对文档进行解析,将事件发送给处理器
        saxParser?.Parse(stream, saxHelper);
        stream?.Close();
        Log.Debug(TAG, SaxHelper.XmlData);
        xmlText.Text = $"SAX ---> \n{SaxHelper.XmlData}";
    };


using Android.Util;
using Org.Xml.Sax;
using Org.Xml.Sax.Helpers;

namespace SecondaryBlankApp.Scripts
{
    internal class SaxHelper : DefaultHandler
    {
        private string TAG = "DataMessage";

        public static string XmlData;

        public override void StartDocument()
        {
            base.StartDocument();
        }

        // localName 开始标签名 attributes 属性数组
        public override void StartElement(string uri, string localName, string qName, IAttributes attributes)
        {
            base.StartElement(uri, localName, qName, attributes);

            string attrString = null;
            for (var i = 0; i < attributes.Length; i++)
                attrString += $" {attributes.GetLocalName(i)}=\"{attributes.GetValue(i)}\"";
            XmlData += $"<{localName}{attrString}>";
            Log.Debug(TAG, $"<{localName}{attrString}>");
        }

        public override void Characters(char[] ch, int start, int length)
        {
            base.Characters(ch, start, length);
            var content = new string(ch, start, length).Trim();
            XmlData += content;
            if (content != string.Empty) Log.Debug(TAG, $"{content}");
        }

        // localName 结束标签名
        public override void EndElement(string uri, string localName, string qName)
        {
            base.EndElement(uri, localName, qName);
            XmlData += $"</{localName}>";
            Log.Debug(TAG, $"</{localName}>\n");
        }

        public override void EndDocument()
        {
            base.EndDocument();
        }
    }
}

DOM

// DOM
private string TAG = "DataMessage";
private string _xmlData = "";

var xmlText = FindViewById<TextView>(Resource.Id.xml_text);

var btn02 = FindViewById<Button>(Resource.Id.btn_02);
if (btn02 != null)
    btn02.Click += delegate
    {
        _xmlData = "";
        // DOM解析器的工厂 dom解析器
        var builder = DocumentBuilderFactory.NewInstance()?.NewDocumentBuilder();
        // 解析的xml文件读入Dom解析器
        var document = builder?.Parse(Assets?.Open("user_info_data.xml"));
        // 文档根节点名称
        if (document?.DocumentElement != null)
        {
            var rootTagName = document.DocumentElement.NodeName;
            // 获取节点列表
            var nodeList = document.GetElementsByTagName(rootTagName);
            GetNodeElement(nodeList);
        }

        Log.Debug(TAG, _xmlData);
        if (xmlText != null) xmlText.Text = $"DOM ---> \n{_xmlData}";
    };
    
    
// 递归获取元素节点和内容
private void GetNodeElement(INodeList nodeList)
{
    for (var i = 0; i < nodeList.Length; i++)
    {
        var node = nodeList.Item(i);
        var attrString = "";
        if (node is { Attributes: { } })
        {
            for (var j = 0; j < node.Attributes.Length; j++)
            {
                var attr = node.Attributes.Item(j);
                if (attr != null) attrString += $" {attr.NodeName}=\"{attr.TextContent}\"";
            }
        }

        if (node == null) continue;
        switch (node.NodeType)
        {
            case Node.ElementNode:
                _xmlData += $"<{node.NodeName}{attrString}>";
                Log.Debug(TAG, $"<{node.NodeName}{attrString}>");
                break;
            case Node.TextNode:
                _xmlData += $"{new string(node.TextContent).Trim()}";
                Log.Debug(TAG, $"{new string(node.TextContent).Trim()}");
                break;
        }

        GetNodeElement(node.ChildNodes);
        if (node.NodeType != Node.ElementNode) continue;
        _xmlData += $"</{node.NodeName}>";
        Log.Debug(TAG, $"</{node.NodeName}>");
    }
}

XmlReader

// XmlReader
private string TAG = "DataMessage";
private string _xmlData = "";

var xmlText = FindViewById<TextView>(Resource.Id.xml_text);

var btn03 = FindViewById<Button>(Resource.Id.btn_03);
if (btn03 != null)
    btn03.Click += async delegate
    {
        _xmlData = "";
        var stream = Assets?.Open("user_info_data.xml");
        var settings = new XmlReaderSettings
        {
            Async = true
        };
        if (stream == null) return;
        var reader = XmlReader.Create(stream, settings);
        while (await reader.ReadAsync())
        {
            switch (reader.NodeType)
            {
                case XmlNodeType.XmlDeclaration:
                    _xmlData += $"<?xml {reader.Value} ?>";
                    Log.Debug(TAG, $"<?xml {reader.Value} ?>");
                    break;
                case XmlNodeType.Element:
                    _xmlData += $"<{reader.Name}";
                    Log.Debug(TAG, $"<{reader.Name}");
                    var attrString = "";
                    if (reader.HasAttributes)
                    {
                        for (var i = 0; i < reader.AttributeCount; i++)
                        {
                            reader.MoveToAttribute(i);
                            attrString += $" {reader.Name}=\"{reader.Value}\"";
                        }
                    }

                    _xmlData += $"{attrString}>";
                    Log.Debug(TAG, $"{attrString}>");
                    break;
                case XmlNodeType.Text:
                    var content = await reader.GetValueAsync();
                    _xmlData += content;
                    Log.Debug(TAG, content);
                    break;
                case XmlNodeType.EndElement:
                    _xmlData += $"</{reader.Name}>";
                    Log.Debug(TAG, $"</{reader.Name}>");
                    break;
            }
        }

        Log.Debug(TAG, _xmlData);
        if (xmlText != null) xmlText.Text = $"XmlReader ---> \n{_xmlData}";
    };