PRB: Error When Setting DateTimePicker Control Programmatically (253785)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 6.0
This article was previously published under Q253785

SYMPTOMS

When attempting to set the date of a DateTimePicker control programmatically, the following error message might appear:
OLE IDispatch exception code 0 from DTPicker: Invalid Property Value.

CAUSE

When using the DateTimePicker control's Calendar interface to change the date, the control handles adjusting the Day, Month, and Year properties to create a valid date. If a value is assigned that creates an invalid date, the error message above is displayed.

RESOLUTION

Use the GOMONTH() function to return a valid date, which can then be used to set the Day, Month, and Year properties of the DateTimePicker control as follows: 
olddate=exampledate
exampledate=exampledate+(number_of_days_to_change)
IF MONTH(exampledate)<>MONTH(olddate)
   olddate=GOMONTH(olddate,-1)
   THISFORM.DTPicker1.DAY=DAY(olddate)
   THISFORM.DTPicker1.MONTH=MONTH(olddate)
   THISFORM.DTPicker1.YEAR=YEAR(olddate)
ENDIF

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a program file named DTP_DEMO using the following code:
    PUBLIC OX
OX=CREATEOBJECT('MYFORM')
OX.SHOW
READ EVENTS

DEFINE CLASS myform AS FORM
   CAPTION = "DateTimePicker Form"
   HEIGHT = 150
   LEFT = 0
   TOP = 0
   WIDTH = 230
   NAME = "myform"

   ADD OBJECT DTPicker1 AS OLECONTROL WITH ;
      OLECLASS="MSComCtl2.DTPicker.2",;
      TOP = 5, ;
      LEFT = 5, ;
      HEIGHT = 25, ;
      WIDTH = 100, ;
      NAME = "DTPicker1"

   ADD OBJECT commandbutton1 AS COMMANDBUTTON WITH ;
      TOP=45, ;
      LEFT=115, ;
      HEIGHT=25, ;
      AUTOSIZE=.T., ;
      CAPTION="Add One Day", ;
      NAME="commandbutton1"

   ADD OBJECT commandbutton2 AS COMMANDBUTTON WITH ;
      TOP=75, ;
      LEFT=115, ;
      HEIGHT=25, ;
      AUTOSIZE=.T., ;
      CAPTION="Subtract One Day", ;
      NAME="commandbutton2"

   ADD OBJECT commandbutton3 AS COMMANDBUTTON WITH ;
      TOP=125, ;
      LEFT=125, ;
      HEIGHT=25, ;
      CAPTION="\<Close", ;
      NAME="commandbutton3"

   PROCEDURE INIT
      PUBLIC exampledate
      exampledate=CTOD("02/01/00")
      THISFORM.DTPicker1.DAY=DAY(exampledate)
      THISFORM.DTPicker1.MONTH=MONTH(exampledate)
      THISFORM.DTPicker1.YEAR=YEAR(exampledate)
   ENDPROC

   PROCEDURE commandbutton1.CLICK
      olddate=exampledate
      exampledate=exampledate+1
*!*	      IF MONTH(exampledate)<>MONTH(olddate)
*!*	         olddate=GOMONTH(olddate,1)
*!*	         THISFORM.DTPicker1.DAY=DAY(olddate)
*!*	         THISFORM.DTPicker1.MONTH=MONTH(olddate)
*!*	         THISFORM.DTPicker1.YEAR=YEAR(olddate)
*!*	      ENDIF
      THISFORM.DTPicker1.DAY=DAY(exampledate)
      THISFORM.DTPicker1.MONTH=MONTH(exampledate)
      THISFORM.DTPicker1.YEAR=YEAR(exampledate)
   ENDPROC

   PROCEDURE commandbutton2.CLICK
      olddate=exampledate
      exampledate=exampledate-1
*!*	      IF MONTH(exampledate)<>MONTH(olddate)
*!*	         olddate=GOMONTH(olddate,-1)
*!*	         THISFORM.DTPicker1.DAY=DAY(olddate)
*!*	         THISFORM.DTPicker1.MONTH=MONTH(olddate)
*!*	         THISFORM.DTPicker1.YEAR=YEAR(olddate)
*!*	      ENDIF
      THISFORM.DTPicker1.DAY=DAY(exampledate)
      THISFORM.DTPicker1.MONTH=MONTH(exampledate)
      THISFORM.DTPicker1.YEAR=YEAR(exampledate)
   ENDPROC

   PROCEDURE commandbutton3.CLICK
      RELEASE THISFORM
   ENDPROC

   PROCEDURE UNLOAD
      CLEAR EVENTS
   ENDPROC

ENDDEFINE
  2. Save and run DTP_DEMO.
  3. Click the Command button captioned Subtract One Day, and note the error message that appears.
  4. Uncomment the commented lines of code in the commandbutton1.click and commandbutton2.click methods.
  5. Save and run DTP_DEMO.
  6. Click the Command button captioned Subtract One Day, and note that the error message does not appear.
(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by John Desch, Microsoft Corporation.

REFERENCES

For additional information DTPicker ActiveX Control, click the article number below to view the article in the Microsoft Knowledge Base:

189991 PRB: Error Setting DateTimePicker's Month Programmatically

Modification Type:MajorLast Reviewed:8/27/2002
Keywords:kbCtrl kbDSupport kbprb KB253785
©2002 Microsoft Corporation. All rights reserved.