HSSFSheet lo_sheet = (HSSFSheet)lo_workbook.CreateSheet("sheet");

         HSSFCellStyle lo_Style = (HSSFCellStyle)lo_workbook.CreateCellStyle();

         lo_Style.DataFormat = HSSFDataFormat.GetBuiltinFormat("@");

         另外附下源码中的注释部分，关于HSSFDataFormat参数的

          0, "General"

           1, "0"

           2, "0.00"

           3, "#,##0"

           4, "#,##0.00"

           5, "($#,##0_);($#,##0)"

           6, "($#,##0_);[Red]($#,##0)"

           7, "($#,##0.00);($#,##0.00)"

           8, "($#,##0.00_);[Red]($#,##0.00)"

           9, "0%"

           0xa, "0.00%"

           0xb, "0.00E+00"

           0xc, "# ?/?"

           0xd, "# ??/??"

           0xe, "m/d/yy"

           0xf, "d-mmm-yy"

           0x10, "d-mmm"

           0x11, "mmm-yy"

           0x12, "h:mm AM/PM"

           0x13, "h:mm:ss AM/PM"

           0x14, "h:mm"

           0x15, "h:mm:ss"

           0x16, "m/d/yy h:mm"

   

            0x17 - 0x24 reserved for international and Undocumented

           0x25, "(#,##0_);(#,##0)"

           0x26, "(#,##0_);[Red](#,##0)"

           0x27, "(#,##0.00_);(#,##0.00)"

           0x28, "(#,##0.00_);[Red](#,##0.00)"

           0x29, "_(///#,##0_);_(///(#,##0);_(/// \"-\"_);_(@_)"

           0x2a, "_($///#,##0_);_($///(#,##0);_($/// \"-\"_);_(@_)"

           0x2b, "_(///#,##0.00_);_(///(#,##0.00);_(///\"-\"??_);_(@_)"

           0x2c, "_($///#,##0.00_);_($///(#,##0.00);_($///\"-\"??_);_(@_)"

           0x2d, "mm:ss"

           0x2e, "[h]:mm:ss"

           0x2f, "mm:ss.0"

           0x30, "##0.0E+0"

           0x31, "@" - This Is text format.

           0x31  "text" - Alias for "@"