[{"DirBarCodeID":1,"DirBarCodeName":"1000001"},
{"DirBarCodeID":3,"DirBarCodeName":"1000002"},
{"DirBarCodeID":4,"DirBarCodeName":"KM1000001"},
{"DirBarCodeID":5,"DirBarCodeName":"KM1000002"}]

{"DirBarCode":
{"DirBarCodeID":1,"DirBarCodeName":"1000001"},
{"DirBarCodeID":3,"DirBarCodeName":"1000002"},
{"DirBarCodeID":6,"DirBarCodeName":"KM1000001"},
{"DirBarCodeID":7,"DirBarCodeName":"KM1000002"}}

 par1 = {"DirBarCode":{"DirBarCodeID":6,"DirBarCodeName":"KM1000001"}} 

        [Serializable]
        public class DirBarCodeElement
        {
            public int? DirBarCodeID;
            public string DirBarCodeName;
        }
        [Serializable]
        public class TableDirBarCode
        {
            public DirBarCodeElement DirBarCode;
        }
        ...
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        TableDirBarCode view = serializer.Deserialize<TableDirBarCode>(par1);
        ...
        int? _DirBarCodeID = view.DirBarCode.DirBarCodeID; //=6
        string _DirBarCodeName = view.DirBarCode.DirBarCodeName; //="KM1000001"