C#中利用Windows的API读写配置参数文件

using System;
using System.CodeDom;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        [DllImport("kernel32")]
        //                        读配置文件方法的6个参数：所在的分区（section）、键值、     初始缺省值、     StringBuilder、   参数长度上限、配置文件路径
        private static extern int GetPrivateProfileString(string section, string key, string deVal, StringBuilder retVal,
            int size, string filePath);

        [DllImport("kernel32")]
        //                            写配置文件方法的4个参数：所在的分区（section）、  键值、     参数值、        配置文件路径
        private static extern long WritePrivateProfileString(string section, string key, string val, string filePath);

        public static void SetValue(string section, string key, string value)
        {
            //获得当前路径，当前是在Debug路径下
            string strPath = Environment.CurrentDirectory + "\\system.ini";
            WritePrivateProfileString(section, key, value, strPath);
        }

        public static string GetValue(string section, string key)
        {
            StringBuilder sb = new StringBuilder(255);
            string strPath = Environment.CurrentDirectory + "\\system.ini";
            //最好初始缺省值设置为非空，因为如果配置文件不存在，取不到值，程序也不会报错
            GetPrivateProfileString(section, key, "配置文件不存在，未取到参数", sb, 255, strPath);
            return sb.ToString();

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            SetValue("参数","波特率","9600");
        }

        private void button1_Click(object sender, EventArgs e)
        {           
            textBox1.Text = GetValue("参数", "波特率");
        }


       
    }
}