using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;

namespace Shentun.Utilities
{
    public class IniFileHelper
    {
        #region API函数声明

        [DllImport("kernel32")]//返回0表示失败，非0为成功
        private static extern long WritePrivateProfileString(string section, string key,
            string val, string filePath);

        [DllImport("kernel32")]//返回取得字符串缓冲区的长度 
        private static extern long GetPrivateProfileString(string section, string key,
            string def, StringBuilder retVal, int size, string filePath);
        #endregion

        public static string Read(string filePath, string section, string key, string defaultValue)
        {
            if (File.Exists(filePath))
            {
                section = section.Trim();
                key = key.Trim();
                defaultValue = defaultValue.Trim();
                StringBuilder temp = new StringBuilder(1024);
                GetPrivateProfileString(section, key, defaultValue, temp, 1024, filePath);
                string returnValue = temp.ToString().Trim();

                return returnValue;
            }
            else
            {
                throw new FileNotFoundException(filePath + "文件不存在");
            }
        }

        public static void Write(string filePath, string section, string key, string value)
        {
            if (File.Exists(filePath))
            {
                section = section.Trim();
                key = key.Trim();
                value = value.Trim();
                StringBuilder temp = new StringBuilder(1024);
                long returnValue = WritePrivateProfileString(section, key, value, filePath);
                if (returnValue == 0)
                {
                    throw new Exception("写入" + filePath + "文件数据失败");
                }
                else
                {
                    return;
                }
            }
            else
            {
                throw new FileNotFoundException(filePath + "文件不存在");
            }
        }

    }
}