C#中没有读写ini文件的类,但用API函数很容易实现.

窗体代码如下:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace IniFileDemo
{
    public partial class Form1 : Form
    {
        /**//**//**//// <summary>
        /// 读ini文件文件API函数声明
        /// </summary>
        /// <param name="section">小节名</param>
        /// <param name="key">关键字</param>
        /// <param name="def">如果没找到时的默认值</param>
        /// <param name="retVal">存放返回值的缓冲区</param>
        /// <param name="size">缓冲区大小</param>
        /// <param name="filePath">要读取的ini文件的路径</param>
        /// <returns>返回读取到的字符数</returns>
        [DllImport("kernel32")]
        private static extern long GetPrivateProfileString(string section, string key, string def, StringBuilder retVal, int size, string filePath);

        /**//**//**//// <summary>
        /// 写ini文件API函数声明
        /// </summary>
        /// <param name="section">小节名</param>
        /// <param name="key">关键字</param>
        /// <param name="val">要写入的值</param>
        /// <param name="filePath">要写入的ini文件的路径</param>
        /// <returns>返回写入的字符数</returns>
        [DllImport("kernel32")]
        private static extern long WritePrivateProfileString(string section, string key, string val, string filePath);

        public Form1()
        {
            InitializeComponent();
        }

        /**//**//**//// <summary>
        /// 从ini文件读取值并应用到窗体的Width,Height属性
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_Load(object sender, EventArgs e)
        {
            StringBuilder myBuilder=new StringBuilder(256);
            GetPrivateProfileString("settings", "width", "300", myBuilder, 256, ".app.ini");
            Width = Int32.Parse(myBuilder.ToString());
            textBox1.Text = Width.ToString();