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Decoding the timestamp in class libararies and forms

  • Article

I was asked

Is there a way to translate the timestamp in a VCX to a human readable format?  

Visual Foxpro puts a timestamp on many records in the table that represents a form or class library. Historically this field was used to match records across supported platforms: DOS, Mac, Unix, Windows.

The VFP reserved variable “_screen” is an object reference to the Form instance that represents the VFP desktop. Because it’s a form instance, you can save it as a class using the SaveAsClass method. This will cause a timestamp record to be created that we can use to run the sample code. The sample code delays 3 seconds, creates a subclass of the form, adds a button, then shows the timestamps of the items in the class library.

The timestamp is in a standard format.

ERASE t.vcx

_screen.AddObject("btn","commandbutton") && add a button to the desktop

_screen.SaveAsClass("t.vcx","myform") && create class myform in a target file t.vcx

INKEY(3) && delay 3 seconds

MODIFY CLASS xx OF t.vcx as myform FROM t.vcx nowait && create a subclass of myform in the same file

ASELOBJ(aArray,1) && get an object reference to the class in the designer

aArray[1].addobject("btn2","commandbutton") && and btn2 to the class

aArray[1].btn2.top=200 && move it down so it doesn't hide btn

KEYBOARD "Y" && a "y" in the "Do you want to save changes")

RELEASE WINDOWS "Class designer" && close the designer

USE t.vcx && open the table

SCAN FOR timestamp!=0 && look for timestamps

      ?timestamp,DecodeTimeStamp(timestamp),objname+" "+class

ENDSCAN

PROCEDURE DecodeTimeStamp(nTimestamp as Number) as Datetime && see https://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/filetimetodosdatetime.asp

nDate=BITRSHIFT(nTimestamp,16)

      nTime=BITAND(nTimestamp,2^16-1)

     

      nYear=BITAND(BITRSHIFT(nDate,9),2^8-1)+1980

      nMonth=BITAND(BITRSHIFT(nDate,5),2^4-1)

      nDay=BITAND(nDate,2^5-1)

      nHr=BITAND(BITRSHIFT(nTime,11),2^5-1)

      nMin=BITAND(BITRSHIFT(nTime,5),2^6-1)

      nSec=BITAND(nTime,2^5-1)

      RETURN DATETIME(nYear,nMonth,nDay,nHr,nMin,nSec)

RETURN

 

48662

Comments

  • Anonymous
    January 22, 2005
    ***********************************
     Name : TimeStamp2DataTime
     Call : tnTimeStamp = 586250725
     ? TimeStamp2DataTime(tnTimeStamp)
     Return : 1997/07/17 15:15:10
     From : Tuberose, Shanghai, China
    **************************************
    tnTimeStamp = 586250725
    ? TimeStamp2DataTime(tnTimeStamp)


    FUNCTION TimeStamp2DataTime
    PARAMETERS lcRetVal
    !     Lparameter tnTimeStamp, tcStyle
    ! Local lcRetVal
    SET DATE YMD
    If Type('tnTimeStamp') <> "N"
    Wait Window "Not Number"
    Return ""
    Endif
    If tnTimeStamp = 0
    Return "Error TimeStamp"
    Endif
    If Type('tcStyle') <> "C"
    tcStyle = "DATETIME"
    Endif
    If .Not. Inlist(Upper(tcStyle), "DATE", "TIME", "DATETIME")
    Wait Window "Type Must is : DATE、TIME or DATETIME"
    Return ""
    Endif
    lnYear = ((tnTimeStamp/(33554432)+1980))
    lnMonth = ((lnYear-Int(lnYear))(33554432))/(2097152)
    lnDay = ((lnMonth-Int(lnMonth))    (2097152))/(65536)
    lnHour = ((lnDay-Int(lnDay))(65536))/(2048)
    lnMinute = ((lnHour-Int(lnHour))    (2048))/(32)
    lnSecond = ((lnMinute-Int(lnMinute))*(32))*2
    lcRetVal = Space(0)
    If "DATE" $ Upper(tcStyle)
    lcRetVal = lcRetVal + Dtoc(Date(lnYear, lnMonth, lnDay))
    Endif
    lcSeparator = ":"
    If "TIME"$Upper(tcStyle)
    lcRetVal = lcRetVal + Iif("DATE" $ Upper(tcStyle), " ", "")
    lcRetVal = lcRetVal + Right("0" + Alltrim(Str(Int(lnHour))), 2)+lcSeparator+;
    Right("0" + Alltrim(Str(Int(lnMinute))), 2) + lcSeparator + ;
    Right("0" + Alltrim(Str(Int(lnSecond))), 2)
    Endif
    Return lcRetVal

  • Anonymous
    January 20, 2009
    PingBack from http://www.hilpers-esp.com/318788-acelerar-el-entorno-de-datos

  • Anonymous
    June 16, 2013
    Function DT2TimeStamp(dtDateTime)  Return   Bitlshift(Bitlshift(Year(dtDateTime)-1980,9)+Bitlshift(Month(dtDateTime),5)+Day(dtDateTime),16) ;    +  BITLSHIFT(hour(dtDatetime),11)+BITlSHIFT(Minute(dtDateTime),5)+Sec(dtDateTime) source : www.atoutfox.org/articles.asp