C#读写ini文件

方式一，用Windows API

using System.Runtime.InteropServices;
using System.Text;

namespace Configure
{
    class IniConfigHelper
    {
        private const int VALUE_MAX_LEN = 1024; //值最大长度

        /// <summary>
        /// 写配置到ini文件
        /// </summary>
        /// <param name="appName">节点名</param>
        /// <param name="keyName">要写入的key</param>
        /// <param name="value">要写入的值</param>
        /// <param name="fileName">要写入ini配置文件路径</param>
        /// <returns>成功返回非0，失败返回0</returns>
        [DllImport("kernel32")]
        private static extern long WritePrivateProfileString(string appName, string keyName,
            string value, string fileName);

        /// <summary>
        /// 从ini配置文件读配置
        /// </summary>
        /// <param name="appName">节点名</param>
        /// <param name="keyName">目标key</param>
        /// <param name="defaultValue">如果找不到目标key就返回这个默认值</param>
        /// <param name="returnedString">返回目标key对应的值</param>
        /// <param name="size">returnedString的大小</param>
        /// <param name="fileName">要读取的ini配置文件路径</param>
        /// <returns>返回返回字符串的长度</returns>

        [DllImport("kernel32")]
        private static extern long GetPrivateProfileString(string appName, string keyName,
            string defaultValue, StringBuilder returnedString, int size, string fileName);

        /// <summary>
        /// 外部接口，写配置
        /// </summary>
        /// <param name="iniFilePath">ini配置文件路径</param>
        /// <param name="appName">节点名</param>
        /// <param name="keyName">key</param>
        /// <param name="value">值</param>
        /// <returns>成功返回true，失败返回false</returns>
        public static bool WriteSetting(string iniFilePath, string appName, string keyName, string value)
        {
            return (0 == WritePrivateProfileString(appName, keyName, value, iniFilePath) ? false : true);
        }

        /// <summary>
        /// 读配置
        /// </summary>
        /// <param name="iniFilePath">ini配置文件路径</param>
        /// <param name="appName">节点名</param>
        /// <param name="keyName">目标key</param>
        /// <param name="defaultValue">默认值</param>
        /// <returns>返回key对应的value</returns>
        public static string ReadSetting(string iniFilePath, string appName, string keyName, string defaultValue)
        {
            StringBuilder result = new StringBuilder(VALUE_MAX_LEN + 1);
            GetPrivateProfileString(appName, keyName, defaultValue, result, VALUE_MAX_LEN, iniFilePath);
            return result.ToString();
        }

    }
}

 

方式二，自己写

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TestReadWriteIniFile
{
    public class IniConfigHelper2
    {
        // 获取key对应的值
        public static bool GetIniKeyString(string filename, string section, string key, ref string val, ref string sErr)
        {

            // 用来标记是否找到section    
            int flag = 0;
            string sSection = "[" + section + "]";

            try
            {
                // 创建一个 StreamReader 的实例来读取文件 
                // using 语句也能关闭 StreamReader
                //using (StreamReader sr = new StreamReader("test.ini", Encoding.UTF8))
                using (StreamReader sr = new StreamReader(filename))
                {
                    string line;

                    // 从文件读取并显示行，直到文件的末尾 
                    while ((line = sr.ReadLine()) != null)
                    {
                        Console.WriteLine(line);
                        int i = line.IndexOf('=');
                        if ((-1 != i) && (1 == flag))
                        {
                            string k = line.Substring(0, i);
                            if (k.Trim() == key)
                            {
                                val = line.Substring(i + 1).Trim();
                                sErr = "";
                                return true;
                            }
                        }
                        else
                        {
                            if (line.Trim() == sSection)
                            {
                                flag = 1;
                            }
                        }
                    }
                }
            }
            catch (Exception e)
            {
                sErr = e.Message;
            }
            return false;
        }
        // 修改key对应的值
        public static bool PutIniKeyString(string filename, string section, string key, string val, ref string sErr)
        {
            // 用来标记是否找到section    
            int flag = 0;
            string sSection = "[" + section + "]";

            try
            {
                StreamReader sr = new StreamReader(filename);
                // 临时文件名
                string tmpFileName = filename + ".tmp";
                StreamWriter sw = new StreamWriter(tmpFileName);
                // 从文件读取并显示行，直到文件的末尾 
                string line;
                while ((line = sr.ReadLine()) != null)
                {
                    if (2 != flag)
                    {
                        int i = line.IndexOf('=');
                        
                        if ((-1 != i) && (1 == flag))
                        {
                            if (key == line.Substring(0, i).Trim())
                            {
                                // 找到对应的key
                                flag = 2;
                                line = key + " = " + val;
                            }
                        }
                        else
                        {
                            if (line.Trim() == sSection)
                            {
                                // 找到section的位置
                                flag = 1;
                            }
                        }
                    }
                    // 写入临时文件
                    sw.WriteLine(line);
                }
                if (1 == flag)
                {
                    line = key + " = " + val;
                    sw.WriteLine(line);
                }
                if (0 == flag)
                {
                    sw.WriteLine(sSection);
                    line = key + " = " + val;
                    sw.WriteLine(line);
                }
                sr.Close();
                sw.Close();
                // 删除源文件
                File.Delete(filename);
                // 临时文件 重命名为 源文件
                File.Move(tmpFileName, filename);
                
                return true;
            }
            catch (Exception e)
            {
                sErr = e.Message;
            }
            return false;
        }
    }
}

//
// 测试代码
            string val=null, sErr=null;
            bool b = IniConfigHelper2.GetIniKeyString(filepath, "DB", "username", ref val, ref sErr)
            val += "123";
            bool b = IniConfigHelper2.PutIniKeyString(filepath, "book2", "name2", "爱我中华", ref sErr);