XML配置文件读取工具类

/// <summary>
/// Author: jxq
/// </summary>
public class XmlConfigReader
{
    #region 获取指定XML路径的XmlDocument对象

    /// <summary>
    /// 根据XML文件路径获取XmlDocument对象
    /// </summary>
    /// <param name="xmlFilePath"></param>
    /// <returns></returns>
    public static XmlDocument GetConfigDoc(string xmlFilePath)
    {
        if (string.IsNullOrEmpty(xmlFilePath) || !File.Exists(xmlFilePath))
            return null;

            
        var xdoc = new XmlDocument();

        try
        {
            xdoc.Load(xmlFilePath);
        }
        catch
        {
            throw new Exception(string.Format("请确认该XML文件格式正确，路径为：{0}", xmlFilePath));
        }

        return xdoc;
    }

    #endregion


    #region 读取节点属性值

    /// <summary>
    /// 读取某个XML节点的属性值（根据属性名）
    /// </summary>
    /// <param name="xmlNode"></param>
    /// <param name="attrName"></param>
    /// <returns></returns>
    public static string ReadAttrValue(XmlNode xmlNode, string attrName)
    {
        return ((XmlElement)xmlNode).GetAttribute(attrName);
    }

    /// <summary>
    /// 读取某个XML文档下某个节点的属性值（根据节点名和属性名）
    /// </summary>
    /// <param name="xmlDoc">XML文档</param>
    /// <param name="nodeName">节点名称</param>
    /// <param name="attrName">属性名</param>
    /// <returns></returns>
    public static string ReadAttrValue(XmlDocument xmlDoc, string nodeName, string attrName)
    {
        var attrVals = ReadAttrValues(xmlDoc, nodeName, attrName);
        return (attrVals == null || attrVals.Length == 0) ? null : attrVals[0];
    }

    /// <summary>
    /// 读取某个XML文档下指定名称的节点的属性值的字符串数组
    /// </summary>
    /// <param name="xmlDoc">XML文档</param>
    /// <param name="nodeName">节点名称</param>
    /// <param name="attrName">属性名</param>
    /// <returns></returns>
    public static string[] ReadAttrValues(XmlDocument xmlDoc, string nodeName, string attrName)
    {
        if (xmlDoc == null || string.IsNullOrEmpty(nodeName) || string.IsNullOrEmpty(attrName))
            return null;

        var xpathExpr = string.Format("//{0}[@{1}]", nodeName, attrName);
        var nodes = GetXmlNodesByXPathExpr(xmlDoc, xpathExpr);
        if (nodes != null && nodes.Count > 0)
        {
            var nodeCount = nodes.Count;
            var attrVals = new string[nodeCount];
            for (var i = 0; i < nodeCount; i++)
            {
                attrVals[i] = ((XmlElement)nodes[i]).GetAttribute(attrName);
            }

            return attrVals;
        }

        return null;
    }

    #endregion


    #region 读取节点文本内容

    /// <summary>
    /// 读取XML文档中节点文本的数组
    /// </summary>
    /// <param name="xmlDoc"></param>
    /// <param name="nodeName"></param>
    /// <returns></returns>
    public static string[] ReadNodeTexts(XmlDocument xmlDoc, string nodeName)
    {
        if (xmlDoc == null || string.IsNullOrEmpty(nodeName))
            return null;

        var xpathExpr = string.Format("//{0}", nodeName);
        var nodes = GetXmlNodesByXPathExpr(xmlDoc, xpathExpr);
        if (nodes != null && nodes.Count > 0)
        {
            var nodeCount = nodes.Count;
            var nodeTexts = new string[nodeCount];
            for (var i = 0; i < nodeCount; i++)
            {
                nodeTexts[i] = nodes[i].InnerText;
            }

            return nodeTexts;
        }

        return null;
    }

    /// <summary>
    /// 读取XML文档中第一个节点名为nodeName的节点的文本
    /// </summary>
    /// <param name="xmlDoc"></param>
    /// <param name="nodeName"></param>
    /// <returns></returns>
    public static string ReadNodeText(XmlDocument xmlDoc, string nodeName)
    {
        var nodeTexts = ReadNodeTexts(xmlDoc, nodeName);
        if (nodeTexts != null && nodeTexts.Length > 0)
        {
            return nodeTexts[0];
        }

        return null;
    }

    /// <summary>
    /// 获取节点文本
    /// </summary>
    /// <param name="xmlNode"></param>
    /// <returns></returns>
    public static string ReadNodeText(XmlNode xmlNode)
    {
        if (xmlNode == null)
            return null;

        return xmlNode.InnerText;
    }

    #endregion


    #region 获取XML节点（或节点列表）

    public static XmlNode GetNodeByName(XmlDocument xmlDoc, string nodeName)
    {
        var nodes = GetXmlNodesByName(xmlDoc, nodeName);
        if (nodes == null || nodes.Count == 0)
            return null;

        return nodes[0];
    }

    /// <summary>
    /// 根据节点名称获取XML文档的节点列表
    /// </summary>
    /// <param name="xmlDoc"></param>
    /// <param name="nodeName">节点名称</param>
    /// <returns></returns>
    public static XmlNodeList GetXmlNodesByName(XmlDocument xmlDoc, string nodeName)
    {
        if (xmlDoc == null || string.IsNullOrEmpty(nodeName))
            return null;

        return GetXmlNodesByXPathExpr(xmlDoc, string.Format("//{0}", nodeName));
    }

    /// <summary>
    /// 获取xmlNode节点下满足xpathExpr表达式的XML结点列表
    /// </summary>
    /// <param name="xmlNode"></param>
    /// <param name="xpathExpr"></param>
    /// <returns></returns>   
    public static XmlNodeList GetXmlNodesByXPathExpr(XmlNode xmlNode, string xpathExpr)
    {
        if (xmlNode == null)
            return null;

        return xmlNode.SelectNodes(xpathExpr);
    }

    #endregion


    #region 根据父节点获取子节点或者子节点的文本

    /// <summary>
    /// 获取父节点下所有子节点的文本数组
    /// </summary>
    /// <param name="parentNode"></param>
    /// <returns></returns>
    public static string[] GetChildTexts(XmlNode parentNode)
    {
        var childNodes = GetChildNodes(parentNode);
        if (childNodes == null || childNodes.Count == 0)
            return null;

        var count = childNodes.Count;
        var childTexts = new string[count];
        var i = 0;
        foreach (XmlNode node in childNodes)
        {
            childTexts[i++] = ReadNodeText(node);
        }

        return childTexts;
    }

    /// <summary>
    /// 获取父节点下所有节点名为childNodeName的子节点的文本数组
    /// </summary>
    /// <param name="parentNode"></param>
    /// <param name="childNodeName"></param>
    /// <returns></returns>
    public static string[] GetChildTexts(XmlNode parentNode, string childNodeName)
    {
        var childNodes = GetChildNodes(parentNode, childNodeName);
        if (childNodes == null || childNodes.Count == 0)
            return null;

        var count = childNodes.Count;
        var childTexts = new string[count];
        var i = 0;
        foreach (XmlNode node in childNodes)
        {
            childTexts[i++] = ReadNodeText(node);
        }

        return childTexts;
    }

    /// <summary>
    /// 获取父节点的子节点列表
    /// </summary>
    /// <param name="parentNode">父节点</param>
    /// <returns></returns>
    public static XmlNodeList GetChildNodes(XmlNode parentNode)
    {
        if (parentNode == null)
            return null;

        return parentNode.ChildNodes;
    }

    /// <summary>
    /// 获取父节点下指定名称的子节点列表
    /// </summary>
    /// <param name="parentNode"></param>
    /// <param name="childNodeName"></param>
    /// <returns></returns>
    public static XmlNodeList GetChildNodes(XmlNode parentNode, string childNodeName)
    {
        return GetXmlNodesByXPathExpr(parentNode, childNodeName);
    }

    #endregion

}