SAP string 转 number 类型

      try.
          cl_fdt_calculation=>convert_string_to_number( exporting  iv_text   = conv #( lwa_atnam-atwrt )
                                                        importing  ev_number = data(l_num) ).
          <lfs_commission>-ratio = l_num.
        catch cx_fdt_conversion.
        catch cx_sy_conversion_overflow.
      endtry.