C#在不区分大小写的情况下比较字符串是否相等

string.Equals(varData_QCMH04.ST_NO.Trim(), tempSteelType, StringComparison.OrdinalIgnoreCase)

public void GetRemoteStandardToLocal()
{
    try
    {
        //MyRegion读取数据库获取原始数据
        using IDbConnection dbConnection = new OracleConnection(str_Conn_AusinL2);
        dbConnection.Open();
        string sqlstr = $"SELECT * FROM  MHQC04_NORMLIZE WHERE ST_NO IS NOT NULL and ISNEW = 1 order by TimeCreated desc";
        var varData_QCMH04 = dbConnection.Query<TbPlc7Mes2BY_MHQC04_Normlize>(sqlstr).FirstOrDefault();
        if (varData_QCMH04 != null)
        {
            //MyRegion将远程数据库数据整理后，去重后，存入本地数据库
            string tempSteelType = "";
            string tempElementName = "";
            double tempElementMax = 0.0;
            double tempElementMin = 0.0;
            double tempElementAim = 0.0;
            if (varData_QCMH04.ST_NO != null)
            {
                if (!string.Equals(varData_QCMH04.ST_NO.Trim(), tempSteelType, StringComparison.OrdinalIgnoreCase))
                {
                    tempSteelType = varData_QCMH04.ST_NO.Trim();

                    for (int i = 0; i < 20; i++)
                    {
                        tempElementName = varData_QCMH04.GetType().GetProperty($"ELM_NAME{i + 1}")?.GetValue(varData_QCMH04)?.ToString().Trim();
                        if (tempElementName != null)
                        {
                            tempElementMax = Convert.ToDouble(varData_QCMH04.GetType().GetProperty($"ELM_MAX{i + 1}")?.GetValue(varData_QCMH04));
                            tempElementMin = Convert.ToDouble(varData_QCMH04.GetType().GetProperty($"ELM_MIN{i + 1}")?.GetValue(varData_QCMH04));
                            tempElementAim = Convert.ToDouble(varData_QCMH04.GetType().GetProperty($"ELM_AIM{i + 1}")?.GetValue(varData_QCMH04));
                            var insert_Model2Main3 = new TbModel2Main3Normlize()
                            {
                                TimeCreated = DateTime.Now,
                                SeqNo = i + 1,
                                IsNew = 1,
                                Id = 0,
                                SteelName = tempSteelType,
                                SteelType = tempSteelType,
                                ElementName = tempElementName,
                                ElementType = tempElementName,
                                StandardMax = tempElementMax,
                                StandardMin = tempElementMin,
                                StandardAim = tempElementAim,
                            };
                            string insertSql = "INSERT INTO TB_MODE2_MAIN3_NORMLIZE " +
                                " (TimeCreated, SeqNo,IsNew,Id, SteelName,SteelType,ElementName,ElementType,StandardMax,StandardMin,StandardAim " +
                                " VALUES (:TimeCreated, :SeqNo, :IsNew, :Id,:SteelName, :SteelType,:ElementName,:ElementType,:StandardMax,:StandardMin,:StandardAim ";
                            int rowsAffected1 = dbConnection.Execute(insertSql, insert_Model2Main3);

                        }
                    }


                }

            }
            varData_QCMH04.IsNew = 0;
            string sqlStr_Update = "UPDATE MHQC04_NORMLIZE SET ISNEW = :ISNEW WHERE TimeCreated = :=TimeCreated and SeqNo = :SeqNo ";
            int rowsAffected2 = dbConnection.Execute(sqlStr_Update, varData_QCMH04);

        }
    }
    catch (Exception ex)
    {

        AppLog.Info("GetRemoteNormlize()出错，信息为: " + ex.Message);
    }

}