C# 使用文件流来读写ini文件

背景

　　之前采用ini文件作为程序的配置文件，觉得这种结构简单明了，配置起来也挺方便。然后操作方式是通过WindowsAPI，然后再网上找到一个基于WindowsAPI封装的help类，用起来倒也顺手。用的多了，觉得还可以使用文件流来操作，后来就发现了EasyConfig。

　　EasyConfig是一个纯C#的开源ini文件操作库，但是在使用上有诸多不便，只是个人感觉，于是个人将其改造了一下，是自己喜欢用的风格。

资源下载

　　如果不清楚ini文件结构，请百度一下，这里贴一个示例文件。

/// <summary>
/// Provides methods for reading and writing to an INI file.
/// </summary>
public class IniFileHelp
{
/// <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="IniFileHelp"/> class.
/// </summary>
/// <param name="path">The ini file to read and write from.</param>
public IniFileHelp(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(IniFileHelp.MaxSectionSize);

NativeMethods.GetPrivateProfileString(sectionName,
keyName,
defaultValue,
retval,
IniFileHelp.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(IniFileHelp.MaxSectionSize);

try
{
//Get the section key/value pairs into the buffer.
int len = NativeMethods.GetPrivateProfileSection(sectionName,
ptr,
IniFileHelp.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
//Cancel a string start with '#'
var item = keyValuePairs[i].Trim();
if (item.Length > 0 && !item.StartsWith("#"))
{
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(IniFileHelp.MaxSectionSize);

try
{
//Get the section names into the buffer.
len = NativeMethods.GetPrivateProfileString(sectionName,
null,
null,
ptr,
IniFileHelp.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(IniFileHelp.MaxSectionSize);

try
{
//Get the section names into the buffer.
len = NativeMethods.GetPrivateProfileSectionNames(ptr,
IniFileHelp.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
}

IniFileHelp