c# 读取ini 文件得不到里面的值怎么回事？？？

急！帮帮忙！类方法： public class CIniIFile
    {
         public string inipath;
         [DllImport("kernel32")]
         private static extern long WritePrivateProfileString(string section,string key,string val,string filePath);
         [DllImport("kernel32")]
         private static extern int GetPrivateProfileString(string section,string key,string def,StringBuilder retVal,int size,string filePath);
         /// <summary>
         /// 构造方法
         /// </summary>
         /// <param name="INIPath">文件路径</param>
         public void INIClass(string INIPath)
         {
          inipath = INIPath;
         }
         /// <summary>
         /// 写入INI文件
         /// </summary>
         /// <param name="Section">项目名称(如 [TypeName] )</param>
         /// <param name="Key">键</param>
         /// <param name="Value">值</param>
         public void IniWriteValue(string Section,string Key,string Value)
         {
          WritePrivateProfileString(Section,Key,Value,this.inipath);
         }
         /// <summary>
         /// 读出INI文件
         /// </summary>
         /// <param name="Section">项目名称(如 [TypeName] )</param>
         /// <param name="Key">键</param>
         public string IniReadValue(string Section,string Key)
         {
          StringBuilder temp = new StringBuilder(500);
          int i = GetPrivateProfileString(Section,Key,"",temp,500,this.inipath);
          return temp.ToString();
         }
         /// <summary>
         /// 验证文件是否存在
         /// </summary>
         /// <returns>布尔值</returns>
         public bool ExistINIFile()
         {
          return File.Exists(inipath);
         }    }执行： private void FormS_Load(object sender, EventArgs e)
        {
            string filestr = System.Windows.Forms.Application.StartupPath + @"\Risun.ini";
            CIniIFile cl = new CIniIFile();
            cl.INIClass(filestr);
            MessageBox.Show(cl.IniReadValue("LOCALSERVER", "User"));             
        }
读取出来总是空的·····到底怎么回事哇？ini中的格式是这样的
[LOCALSERVER]
Server=192.168.1.100
User=sa
Pwd=sasasa