?using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.IO;

/// <summary>
/// xml 配置文件類
/// </summary>
public class Comm_Xml
{
    private string FileName;
    private string rootNode = "Setting";

    #region 構造
    public Comm_Xml(string sFileName)
    {
        FileName = sFileName;
        //不存在創建
        if (!File.Exists(sFileName))
        {
            XmlTextWriter xtw = new XmlTextWriter(sFileName, Encoding.UTF8);
            xtw.Formatting = Formatting.Indented;
            xtw.WriteStartDocument();
            xtw.WriteStartElement(rootNode);
            xtw.WriteEndElement();
            xtw.WriteEndDocument();
            xtw.Close();
        }
    }
    #endregion

    #region 寫配置
    /// <summary>
    /// 寫配置文件
    /// </summary>
    /// <param name="Section">主鍵</param>
    /// <param name="Key">子鍵</param>
    /// <param name="Value">寫入值</param>
    public void WriteString(string Section, string Key, string Value)
    {
        bool bSectionExists = false;
        bool bKeyExists = false;
        XmlElement xe = null;

        XmlDocument xmldoc = new XmlDocument();
        xmldoc.Load(FileName);

        XmlNode root = xmldoc.SelectSingleNode(rootNode);
        XmlNodeList rootlist = root.ChildNodes;

        foreach (XmlNode xn in rootlist)
        {
            if (xn.Name == Section) //遍歷子節點
            {
                xe = (XmlElement)xn;
                bSectionExists = true;
                XmlNodeList subrootlist = xn.ChildNodes;
                foreach (XmlNode xnsub in subrootlist)
                {
                    if (xnsub.Name == Key)
                    {
                        xnsub.InnerText = Value;
                        bKeyExists = true;
                        break;
                    }
                }
            }
        }

        //父節點不存在處理
        if (!bSectionExists)
        {
            xe = xmldoc.CreateElement(Section);
            root.AppendChild(xe);
        }
        //子節點不存在處理
        if (!bKeyExists)
        {
            XmlElement xe1 = xmldoc.CreateElement(Key);
            xe1.InnerText = Value;
            xe.AppendChild(xe1);
        }
        xmldoc.Save(FileName);
    }
    #endregion

    #region 讀配置
    /// <summary>
    /// 讀配置文件
    /// </summary>
    /// <param name="Section">主鍵</param>
    /// <param name="Key">子鍵</param>
    /// <param name="DefaultValue">不存在默認返回值</param>
    /// <returns>字符串值</returns>
    public string ReadString(string Section, string Key, string DefaultValue)
    {
        XmlDocument xmldoc = new XmlDocument();
        xmldoc.Load(FileName);

        XmlNode root = xmldoc.SelectSingleNode(rootNode);
        XmlNodeList rootlist = root.ChildNodes;

        foreach (XmlNode xn in rootlist)
        {
            if (xn.Name == Section) //遍歷子節點
            {
                XmlNodeList subrootlist = xn.ChildNodes;
                foreach (XmlNode xnsub in subrootlist)
                {
                    if (xnsub.Name == Key)
                    {
                        return xnsub.InnerText;
                    }
                }
            }
        }
        return DefaultValue;
    }
    #endregion

    #region 刪除配置
    /// <summary>
    /// 刪除配置
    /// </summary>
    /// <param name="Section">主鍵</param>
    /// <param name="Key">子鍵，為 null 時刪除主鍵</param>
    public void DelKey(string Section, string Key)
    {
        XmlDocument xmldoc = new XmlDocument();
        xmldoc.Load(FileName);

        XmlNode root = xmldoc.SelectSingleNode(rootNode);
        XmlNodeList rootlist = root.ChildNodes;

        foreach (XmlNode xn in rootlist)
        {
            if (xn.Name == Section) //遍歷子節點
            {
                if (Key == null) //整個主鍵刪除
                {
                    root.RemoveChild(xn);
                    break;;
                }
                XmlNodeList subrootlist = xn.ChildNodes;
                foreach (XmlNode xnsub in subrootlist)
                {
                    if (xnsub.Name == Key)
                    {
                        xn.RemoveChild(xnsub);
                        break;
                    }
                }
            }
        }
        xmldoc.Save(FileName);
    }
    #endregion
}