class ZT_INI
{
    /************************************************************************/
    /*写操作
     * strSection   节
     * strKey       键
     * strValue     需要写入的值
     * strFilePath  配置文件的全路径（wince中只能使用绝对全路径）
     */
    /************************************************************************/

    public static void PutINI(string strSection, string strKey, string strValue, string strFilePath)
    {
        INICommon(false, strSection, strKey, strValue, strFilePath);
    }

    /************************************************************************/
    /* 读操作
     * strSection   节
     * strKey       键
     * strDefault   如果未找到相应键对应的值则填入此值
     * strFilePath  配置文件的全路径（wince中只能使用绝对全路径）
     * 返回：       指定键的相应值
     * 说明：       如果在文件中未找到相应节则添加，未找到相应键亦添加，如果键对应的值为空串则使用默认值填充ini文件并返回
    /************************************************************************/

    public static string GetINI(string strSection, string strKey, string strDefault, string strFilePath)
    {
        return INICommon(true, strSection, strKey, strDefault, strFilePath);
    }

    private static string[] Split(string input, string pattern)
    {
        string[] arr = System.Text.RegularExpressions.Regex.Split(input, pattern);
        return arr;
    }
    private static void AppendToFile(string strPath, string strContent)
    {
        FileStream fs = new FileStream(strPath, FileMode.Append);
        StreamWriter streamWriter = new StreamWriter(fs, System.Text.Encoding.Default);
        streamWriter.BaseStream.Seek(0, SeekOrigin.End);
        streamWriter.WriteLine(strContent);
        streamWriter.Flush();
        streamWriter.Close();
        fs.Close();
    }
    private static void WriteArray(string strPath, string[] strContent)
    {
        FileStream fs = new FileStream(strPath, FileMode.Truncate);
        StreamWriter streamWriter = new StreamWriter(fs, System.Text.Encoding.Default);
        streamWriter.BaseStream.Seek(0, SeekOrigin.Begin);

        for (int i = 0; i < strContent.Length; i++)
        {
            if (strContent[i].Trim() == "\r\n")
                continue;
            streamWriter.WriteLine(strContent[i].Trim());
        }

        streamWriter.Flush();
        streamWriter.Close();
        fs.Close();
    }
    //INI解析
    private static string INICommon(bool isRead, string ApplicationName, string KeyName, string Default, string FileName)
    {
        string strSection = "[" + ApplicationName + "]";
        string strBuf;
        try
        {
            //a.文件不存在则创建
            if (!File.Exists(FileName))
            {
                FileStream sr = File.Create(FileName);
                sr.Close();
            }
            //读取INI文件
            System.IO.StreamReader stream = new System.IO.StreamReader(FileName, System.Text.Encoding.Default);
            strBuf = stream.ReadToEnd();//读取ini文件
            stream.Close();
        }
        catch (Exception e)
        {
            MessageBox.Show(e.ToString(), "INI文件读取异常");
            return Default;
        }

        string[] rows = Split(strBuf, "\r\n");
        string oneRow;
        int i = 0;
        for (; i < rows.Length; i++)
        {
            oneRow = rows[i].Trim();

            //空行
            if (0 == oneRow.Length)
                continue;

            //此行为注释
            if (‘;‘ == oneRow[0])
                continue;

            //没找到
            if (strSection != oneRow)
                continue;

            //找到了
            break;
        }

        //b.没找到对应的section，创建一节并创建属性
        if (i >= rows.Length)
        {
            AppendToFile(FileName, "\r\n" + strSection + "\r\n" + KeyName + "=" + Default);
            return Default;
        }

        //找到section

        i += 1; //跳过section 

        int bakIdxSection = i;//备份section的下一行

        string[] strLeft;

        //查找属性
        for (; i < rows.Length; i++)
        {
            oneRow = rows[i].Trim();

            //空行
            if (0 == oneRow.Length)
                continue;

            //此行为注释
            if (‘;‘ == oneRow[0])
                continue;

            //越界
            if (‘[‘ == oneRow[0])
                break;

            strLeft = Split(oneRow, "=");

            if (strLeft == null || strLeft.Length != 2)
                continue;

            //找到属性
            if (strLeft[0].Trim() == KeyName)
            {
                //读
                if (isRead)
                {
                    //c.找到属性但没有值
                    if (0 == strLeft[1].Trim().Length)
                    {
                        rows[i] = strLeft[0].Trim() + "=" + Default;
                        WriteArray(FileName, rows);
                        return Default;
                    }
                    else
                    {
                        //找到了                        
                        return strLeft[1].Trim();
                    }
                }

                //写
                else
                {
                    rows[i] = strLeft[0].Trim() + "=" + Default;
                    WriteArray(FileName, rows);
                    return Default;
                }
            }
        }

        //d.没找到对应的属性,创建之并赋为默认
        rows[bakIdxSection] = rows[bakIdxSection] + "\r\n" + KeyName + "=" + Default;
        WriteArray(FileName, rows);
        return Default;
    }
}

//文件路径
string filePath = System.IO.Path.Combine(Common.Root, "config");
//读
string strGet = ZT_INI.GetINI("配置", "ip1", "", filePath);
//写
ZT_INI.PutINI("配置", "ip1", strGet, filePath);