C# help

A file format for saving data like XML.

Example file this is actually used in my program that I am developing right now.


[Settings]

Download_Directory=%CURRENT_DIR%\Downloads

Latest_Revision_URL=http://build.chromium.org/f/chromium/snapshots/Win_Webkit_Latest/LATEST

Specific_Revision_URL=http://build.chromium.org/f/chromium/snapshots/Win_Webkit_Latest/

Start_Hidden=1

Update_Frequency=60

The class I use


using System;

using System.Collections.Generic;

using System.Globalization;

using System.Runtime.InteropServices;

using System.Text;


    public class IniFile

    {

        /// <summary>

        /// The maximum size of a section in an ini file.

        /// </summary>

        /// <remarks>

        /// This property defines the maximum size of the buffers 

        /// used to retreive data from an ini file.  This value is 

        /// the maximum allowed by the win32 functions 

        /// GetPrivateProfileSectionNames() or 

        /// GetPrivateProfileString().

        /// </remarks>

        public const int MaxSectionSize = 32767; // 32 KB


        //The path of the file we are operating on.

        private string m_path;


        #region P/Invoke declares


        /// <summary>

        /// A static class that provides the win32 P/Invoke signatures 

        /// used by this class.

        /// </summary>

        /// <remarks>

        /// Note:  In each of the declarations below, we explicitly set CharSet to 

        /// Auto.  By default in C#, CharSet is set to Ansi, which reduces 

        /// performance on windows 2000 and above due to needing to convert strings

        /// from Unicode (the native format for all .Net strings) to Ansi before 

        /// marshalling.  Using Auto lets the marshaller select the Unicode version of 

        /// these functions when available.

        /// </remarks>

        [System.Security.SuppressUnmanagedCodeSecurity]

        private static class NativeMethods

        {

            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern int GetPrivateProfileSectionNames(IntPtr lpszReturnBuffer,

                                                                   uint nSize,

                                                                   string lpFileName);


            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern uint GetPrivateProfileString(string lpAppName,

                                                              string lpKeyName,

                                                              string lpDefault,

                                                              StringBuilder lpReturnedString,

                                                              int nSize,

                                                              string lpFileName);


            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern uint GetPrivateProfileString(string lpAppName,

                                                              string lpKeyName,

                                                              string lpDefault,

                                                              [In, Out] char[] lpReturnedString,

                                                              int nSize,

                                                              string lpFileName);


            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern int GetPrivateProfileString(string lpAppName,

                                                             string lpKeyName,

                                                             string lpDefault,

                                                             IntPtr lpReturnedString,

                                                             uint nSize,

                                                             string lpFileName);


            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern int GetPrivateProfileInt(string lpAppName,

                                                          string lpKeyName,

                                                          int lpDefault,

                                                          string lpFileName);


            [DllImport("kernel32.dll", CharSet = CharSet.Auto)]

            public static extern int GetPrivateProfileSection(string lpAppName,

                                                              IntPtr lpReturnedString,

                                                              uint nSize,

                                                              string lpFileName);


            //We explicitly enable the SetLastError attribute here because

            // WritePrivateProfileString returns errors via SetLastError.

            // Failure to set this can result in errors being lost during 

            // the marshal back to managed code.

            [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]

            public static extern bool WritePrivateProfileString(string lpAppName,

                                                                string lpKeyName,

                                                                string lpString,

                                                                string lpFileName);



        }

        #endregion


        /// <summary>

        /// Initializes a new instance of the <see cref="IniFile"/> class.

        /// </summary>

        /// <param name="path">The ini file to read and write from.</param>

        public IniFile(string path)

        {

            //Convert to the full path.  Because of backward compatibility, 

            // the win32 functions tend to assume the path should be the 

            // root Windows directory if it is not specified.  By calling 

            // GetFullPath, we make sure we are always passing the full path

            // the win32 functions.

            m_path = System.IO.Path.GetFullPath(path);

        }


        /// <summary>

        /// Gets the full path of ini file this object instance is operating on.

        /// </summary>

        /// <value>A file path.</value>

        public string Path

        {

            get

            {

                return m_path;

            }

        }


        #region Get Value Methods


        /// <summary>

        /// Gets the value of a setting in an ini file as a <see cref="T:System.String"/>.

        /// </summary>

        /// <param name="sectionName">The name of the section to read from.</param>

        /// <param name="keyName">The name of the key in section to read.</param>

        /// <param name="defaultValue">The default value to return if the key

        /// cannot be found.</param>

        /// <returns>The value of the key, if found.  Otherwise, returns 

        /// <paramref name="defaultValue"/></returns>

        /// <remarks>

        /// The retreived value must be less than 32KB in length.

        /// </remarks>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public string GetString(string sectionName,

                                string keyName,

                                string defaultValue)

        {

            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            if (keyName == null)

                throw new ArgumentNullException("keyName");


            StringBuilder retval = new StringBuilder(IniFile.MaxSectionSize);


            NativeMethods.GetPrivateProfileString(sectionName,

                                                  keyName,

                                                  defaultValue,

                                                  retval,

                                                  IniFile.MaxSectionSize,

                                                  m_path);


            return retval.ToString();

        }


        /// <summary>

        /// Gets the value of a setting in an ini file as a <see cref="T:System.Int16"/>.

        /// </summary>

        /// <param name="sectionName">The name of the section to read from.</param>

        /// <param name="keyName">The name of the key in section to read.</param>

        /// <param name="defaultValue">The default value to return if the key

        /// cannot be found.</param>

        /// <returns>The value of the key, if found.  Otherwise, returns 

        /// <paramref name="defaultValue"/>.</returns>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public int GetInt16(string sectionName,

                            string keyName,

                            short defaultValue)

        {

            int retval = GetInt32(sectionName, keyName, defaultValue);


            return Convert.ToInt16(retval);

        }


        /// <summary>

        /// Gets the value of a setting in an ini file as a <see cref="T:System.Int32"/>.

        /// </summary>

        /// <param name="sectionName">The name of the section to read from.</param>

        /// <param name="keyName">The name of the key in section to read.</param>

        /// <param name="defaultValue">The default value to return if the key

        /// cannot be found.</param>

        /// <returns>The value of the key, if found.  Otherwise, returns 

        /// <paramref name="defaultValue"/></returns>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public int GetInt32(string sectionName,

                            string keyName,

                            int defaultValue)

        {

            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            if (keyName == null)

                throw new ArgumentNullException("keyName");



            return NativeMethods.GetPrivateProfileInt(sectionName, keyName, defaultValue, m_path);

        }


        /// <summary>

        /// Gets the value of a setting in an ini file as a <see cref="T:System.Double"/>.

        /// </summary>

        /// <param name="sectionName">The name of the section to read from.</param>

        /// <param name="keyName">The name of the key in section to read.</param>

        /// <param name="defaultValue">The default value to return if the key

        /// cannot be found.</param>

        /// <returns>The value of the key, if found.  Otherwise, returns 

        /// <paramref name="defaultValue"/></returns>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public double GetDouble(string sectionName,

                                string keyName,

                                double defaultValue)

        {

            string retval = GetString(sectionName, keyName, "");


            if (retval == null || retval.Length == 0)

            {

                return defaultValue;

            }


            return Convert.ToDouble(retval, CultureInfo.InvariantCulture);

        }


        #endregion


        #region GetSectionValues Methods


        /// <summary>

        /// Gets all of the values in a section as a list.

        /// </summary>

        /// <param name="sectionName">

        /// Name of the section to retrieve values from.

        /// </param>

        /// <returns>

        /// A <see cref="List{T}"/> containing <see cref="KeyValuePair{T1, T2}"/> objects 

        /// that describe this section.  Use this verison if a section may contain

        /// multiple items with the same key value.  If you know that a section 

        /// cannot contain multiple values with the same key name or you don't 

        /// care about the duplicates, use the more convenient 

        /// <see cref="GetSectionValues"/> function.

        /// </returns>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> is a null reference  (Nothing in VB)

        /// </exception>

        public List<KeyValuePair<string, string>> GetSectionValuesAsList(string sectionName)

        {

            List<KeyValuePair<string, string>> retval;

            string[] keyValuePairs;

            string key, value;

            int equalSignPos;


            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            //Allocate a buffer for the returned section names.

            IntPtr ptr = Marshal.AllocCoTaskMem(IniFile.MaxSectionSize);


            try

            {

                //Get the section key/value pairs into the buffer.

                int len = NativeMethods.GetPrivateProfileSection(sectionName,

                                                                 ptr,

                                                                 IniFile.MaxSectionSize,

                                                                 m_path);


                keyValuePairs = ConvertNullSeperatedStringToStringArray(ptr, len);

            }

            finally

            {

                //Free the buffer

                Marshal.FreeCoTaskMem(ptr);

            }


            //Parse keyValue pairs and add them to the list.

            retval = new List<KeyValuePair<string, string>>(keyValuePairs.Length);


            for (int i = 0; i < keyValuePairs.Length; ++i)

            {

                //Parse the "key=value" string into its constituent parts

                equalSignPos = keyValuePairs[i].IndexOf('=');


                key = keyValuePairs[i].Substring(0, equalSignPos);


                value = keyValuePairs[i].Substring(equalSignPos + 1,

                                                   keyValuePairs[i].Length - equalSignPos - 1);


                retval.Add(new KeyValuePair<string, string>(key, value));

            }


            return retval;

        }


        /// <summary>

        /// Gets all of the values in a section as a dictionary.

        /// </summary>

        /// <param name="sectionName">

        /// Name of the section to retrieve values from.

        /// </param>

        /// <returns>

        /// A <see cref="Dictionary{T, T}"/> containing the key/value 

        /// pairs found in this section.  

        /// </returns>

        /// <remarks>

        /// If a section contains more than one key with the same name, 

        /// this function only returns the first instance.  If you need to 

        /// get all key/value pairs within a section even when keys have the 

        /// same name, use <see cref="GetSectionValuesAsList"/>.

        /// </remarks>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> is a null reference  (Nothing in VB)

        /// </exception>

        public Dictionary<string, string> GetSectionValues(string sectionName)

        {

            List<KeyValuePair<string, string>> keyValuePairs;

            Dictionary<string, string> retval;


            keyValuePairs = GetSectionValuesAsList(sectionName);


            //Convert list into a dictionary.

            retval = new Dictionary<string, string>(keyValuePairs.Count);


            foreach (KeyValuePair<string, string> keyValuePair in keyValuePairs)

            {

                //Skip any key we have already seen.

                if (!retval.ContainsKey(keyValuePair.Key))

                {

                    retval.Add(keyValuePair.Key, keyValuePair.Value);

                }

            }


            return retval;

        }


        #endregion


        #region Get Key/Section Names


        /// <summary>

        /// Gets the names of all keys under a specific section in the ini file.

        /// </summary>

        /// <param name="sectionName">

        /// The name of the section to read key names from.

        /// </param>

        /// <returns>An array of key names.</returns>

        /// <remarks>

        /// The total length of all key names in the section must be 

        /// less than 32KB in length.

        /// </remarks>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> is a null reference  (Nothing in VB)

        /// </exception>

        public string[] GetKeyNames(string sectionName)

        {

            int len;

            string[] retval;


            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            //Allocate a buffer for the returned section names.

            IntPtr ptr = Marshal.AllocCoTaskMem(IniFile.MaxSectionSize);


            try

            {

                //Get the section names into the buffer.

                len = NativeMethods.GetPrivateProfileString(sectionName,

                                                            null,

                                                            null,

                                                            ptr,

                                                            IniFile.MaxSectionSize,

                                                            m_path);


                retval = ConvertNullSeperatedStringToStringArray(ptr, len);

            }

            finally

            {

                //Free the buffer

                Marshal.FreeCoTaskMem(ptr);

            }


            return retval;

        }


        /// <summary>

        /// Gets the names of all sections in the ini file.

        /// </summary>

        /// <returns>An array of section names.</returns>

        /// <remarks>

        /// The total length of all section names in the section must be 

        /// less than 32KB in length.

        /// </remarks>

        public string[] GetSectionNames()

        {

            string[] retval;

            int len;


            //Allocate a buffer for the returned section names.

            IntPtr ptr = Marshal.AllocCoTaskMem(IniFile.MaxSectionSize);


            try

            {

                //Get the section names into the buffer.

                len = NativeMethods.GetPrivateProfileSectionNames(ptr,

                    IniFile.MaxSectionSize, m_path);


                retval = ConvertNullSeperatedStringToStringArray(ptr, len);

            }

            finally

            {

                //Free the buffer

                Marshal.FreeCoTaskMem(ptr);

            }


            return retval;

        }


        /// <summary>

        /// Converts the null seperated pointer to a string into a string array.

        /// </summary>

        /// <param name="ptr">A pointer to string data.</param>

        /// <param name="valLength">

        /// Length of the data pointed to by <paramref name="ptr"/>.

        /// </param>

        /// <returns>

        /// An array of strings; one for each null found in the array of characters pointed

        /// at by <paramref name="ptr"/>.

        /// </returns>

        private static string[] ConvertNullSeperatedStringToStringArray(IntPtr ptr, int valLength)

        {

            string[] retval;


            if (valLength == 0)

            {

                //Return an empty array.

                retval = new string[0];

            }

            else

            {

                //Convert the buffer into a string.  Decrease the length 

                //by 1 so that we remove the second null off the end.

                string buff = Marshal.PtrToStringAuto(ptr, valLength - 1);


                //Parse the buffer into an array of strings by searching for nulls.

                retval = buff.Split('\0');

            }


            return retval;

        }


        #endregion


        #region Write Methods


        /// <summary>

        /// Writes a <see cref="T:System.String"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The string value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        private void WriteValueInternal(string sectionName, string keyName, string value)

        {

            if (!NativeMethods.WritePrivateProfileString(sectionName, keyName, value, m_path))

            {

                throw new System.ComponentModel.Win32Exception();

            }

        }


        /// <summary>

        /// Writes a <see cref="T:System.String"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The string value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> or 

        /// <paramref name="value"/>  are a null reference  (Nothing in VB)

        /// </exception>

        public void WriteValue(string sectionName, string keyName, string value)

        {

            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            if (keyName == null)

                throw new ArgumentNullException("keyName");


            if (value == null)

                throw new ArgumentNullException("value");


            WriteValueInternal(sectionName, keyName, value);

        }


        /// <summary>

        /// Writes an <see cref="T:System.Int16"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        public void WriteValue(string sectionName, string keyName, short value)

        {

            WriteValue(sectionName, keyName, (int)value);

        }


        /// <summary>

        /// Writes an <see cref="T:System.Int32"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public void WriteValue(string sectionName, string keyName, int value)

        {

            WriteValue(sectionName, keyName, value.ToString(CultureInfo.InvariantCulture));

        }


        /// <summary>

        /// Writes an <see cref="T:System.Single"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public void WriteValue(string sectionName, string keyName, float value)

        {

            WriteValue(sectionName, keyName, value.ToString(CultureInfo.InvariantCulture));

        }


        /// <summary>

        /// Writes an <see cref="T:System.Double"/> value to the ini file.

        /// </summary>

        /// <param name="sectionName">The name of the section to write to .</param>

        /// <param name="keyName">The name of the key to write to.</param>

        /// <param name="value">The value to write</param>

        /// <exception cref="T:System.ComponentModel.Win32Exception">

        /// The write failed.

        /// </exception>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public void WriteValue(string sectionName, string keyName, double value)

        {

            WriteValue(sectionName, keyName, value.ToString(CultureInfo.InvariantCulture));

        }


        #endregion


        #region Delete Methods


        /// <summary>

        /// Deletes the specified key from the specified section.

        /// </summary>

        /// <param name="sectionName">

        /// Name of the section to remove the key from.

        /// </param>

        /// <param name="keyName">

        /// Name of the key to remove.

        /// </param>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> or <paramref name="keyName"/> are 

        /// a null reference  (Nothing in VB)

        /// </exception>

        public void DeleteKey(string sectionName, string keyName)

        {

            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            if (keyName == null)

                throw new ArgumentNullException("keyName");


            WriteValueInternal(sectionName, keyName, null);

        }


        /// <summary>

        /// Deletes a section from the ini file.

        /// </summary>

        /// <param name="sectionName">

        /// Name of the section to delete.

        /// </param>

        /// <exception cref="ArgumentNullException">

        /// <paramref name="sectionName"/> is a null reference (Nothing in VB)

        /// </exception>

        public void DeleteSection(string sectionName)

        {

            if (sectionName == null)

                throw new ArgumentNullException("sectionName");


            WriteValueInternal(sectionName, null, null);

        }


        #endregion

    }