1、C#操作INI的方法一般是采用调用DLL中的INI文件的函数

#region 导入DLL函数
[DllImport("kernel32.dll")]
public extern static int GetPrivateProfileString(string segName, string keyName, string sDefault, StringBuilder buffer, int nSize, string fileName);

public extern static int GetPrivateProfileStringA(string segName, string keyName, string sDefault, byte[] buffer, int iLen, string fileName); // ANSI版本

[DllImport("kernel32.dll")]
public extern static int GetPrivateProfileSection(string segName, StringBuilder buffer, int nSize, string fileName);

[DllImport("kernel32.dll")]
public extern static int WritePrivateProfileSection(string segName, string sValue, string fileName);

[DllImport("kernel32.dll")]
public extern static int WritePrivateProfileString(string segName, string keyName, string sValue, string fileName);

[DllImport("kernel32.dll")]
public extern static int GetPrivateProfileSectionNamesA(byte[] buffer, int iLen, string fileName);

#endregion

2、 INI文件的fileName必须使用绝对路径，说明如下

If the lpFileName parameter does not contain a full path and file name for the file,
WritePrivateProfileString searches the Windows directory for the file.
If the file does not exist,this function creates the file in the Windows directory.

3、封装的方法中，最有价值的是获取所有Sections和所有的Keys，网上关于这个的代码大部分是错误的，这里给出一个正确的方法：

/// 返回该配置文件中所有Section名称的集合

public ArrayList ReadSections() {
byte[] buffer = new byte[65535];
int rel = GetPrivateProfileSectionNamesA(buffer, buffer.GetUpperBound(0), _FileName);
int iCnt, iPos;
ArrayList arrayList = new ArrayList();
string tmp;
if (rel>0) {
iCnt = 0; iPos = 0;
for (iCnt = 0; iCnt < rel; iCnt++) {
if (buffer[iCnt] == 0x00) {
tmp =System.Text.ASCIIEncoding.Default.GetString(buffer, iPos, iCnt-iPos ).Trim();
iPos = iCnt + 1;
if (tmp != "")
arrayList.Add(tmp);
}
}
}
return arrayList;
}

// 获取节点的所有KEY值

public ArrayList ReadKeys(string sectionName) {

byte[] buffer = new byte[5120];
int rel = GetPrivateProfileStringA(sectionName, null, "", buffer, buffer.GetUpperBound(0), _FileName);

int iCnt, iPos;
ArrayList arrayList = new ArrayList();
string tmp;
if (rel > 0) {
iCnt = 0; iPos = 0;
for (iCnt = 0; iCnt < rel; iCnt++) {
if (buffer[iCnt] == 0x00) {
tmp = System.Text.ASCIIEncoding.Default.GetString(buffer, iPos, iCnt-iPos).Trim();
iPos = iCnt + 1;
if (tmp != "")
arrayList.Add(tmp);
}
}
}
return arrayList;
}

4、批判网上一个常见的代码范例

public string ReadString(string Section, string Key) {
StringBuilder buffer= new StringBuilder(65535);
GetPrivateProfileString(Section, Key, "", buffer, buffer.Capacity, _FileName);
return buffer.ToString();
}

用StringBuilder只能读出第一行，不是一个好的写法，正确的做法应该是用char[],因为返回的是一个二进制的串，字符串之间是用"\0"分隔的，具体的见我前面的代码。

 GetString("Section", "Key");

 public string GetString(string Section, string Key)
    {
        string basedirectory = System.AppDomain.CurrentDomain.BaseDirectory;
        string path = Path.Combine(basedirectory, "vehstat.ini");
        StringBuilder temp = new StringBuilder(500);
        int i = GetPrivateProfileString(Section, Key, "", temp, 500, path);
        return temp.ToString();
    }