Q193967: HOWTO: Determine the New Month Selected in Calendar Control

Article: Q193967
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SUMMARY
=======

The Microsoft Calendar Control provides NewMonth and NewYear events. These
events occur when the user selects a different month or year in the Calendar.
However, the events do not indicate which month or year was selected. This
article demonstrates how you can determine which month or year was selected.

MORE INFORMATION
================

The Microsoft Calendar control does not ship with Visual Basic. The control
ships as part of Microsoft Access or may be downloaded for free from the
following URL:

  http://www.microsoft.com/officedev/freestuff/mscaldl.htm

Step-by-Step Example
--------------------

1. Start Visual Basic and create a new Standard EXE project. Form1 is created by
  default.

2. On the Project menu, click Components, and then check the "Microsoft Calendar
  Control 8.0" component. The Calendar control is made available on the
  Toolbox.

3. Put a Calendar control on Form1.

4. Copy and paste the following code to the form's code window:

        Option Explicit
        Private Declare Function FindWindowEx Lib "user32" _
           Alias "FindWindowExA" _
           (ByVal hWnd1 As Long, _
           ByVal hWnd2 As Long, _
           ByVal lpsz1 As String, _
           ByVal lpsz2 As String) As Long

        Private Declare Function SendMessage Lib "user32" _
           Alias "SendMessageA" _
           (ByVal hwnd As Long, _
           ByVal wMsg As Long, _
           ByVal wParam As Long, _
           lParam As Any) As Long

        Private Const CB_GETCURSEL = &H147
        Private Const CB_GETLBTEXT = &H148
        Private calendarHwnd As Long
        Private cboMonthHwnd As Long
        Private cboYearHwnd As Long

        Private Sub Form_Load()
           calendarHwnd = FindWindowEx(Me.hwnd, 0&, "CalendarWndClass", _
              vbNullString)
           cboMonthHwnd = FindWindowEx(calendarHwnd, 0&, "ComboBox", _
              vbNullString)
         cboYearHwnd = FindWindowEx(calendarHwnd, cboMonthHwnd, "ComboBox", _
              vbNullString)
        End Sub

        Private Sub Calendar1_NewMonth()
           Dim monthIndex As Long, temp As Long
           Dim ret As String * 255
           ret = Space(255)
           ' Find 0-based index of the selected item:
           monthIndex = SendMessage(cboMonthHwnd, CB_GETCURSEL, 0&, 0&)
           ' Put month name in ret and length of month name in temp:
           temp = SendMessage(cboMonthHwnd, CB_GETLBTEXT, monthIndex, _
               ByVal ret)
           ' uncomment the line below to see if the ComboBox was used:
           'If Calendar1.Month = 0 Then Debug.Print "ComboBox used to
           'select";
           Debug.Print Left(ret, temp) 'Displays Month Name
        End Sub

        Private Sub Calendar1_NewYear()
           Dim yearIndex As Long, temp As Long
           Dim ret As String * 255
           ret = Space(255)
           ' Find 0-based index of the selected item:
           yearIndex = SendMessage(cboYearHwnd, CB_GETCURSEL, 0&, 0&)
           ' Put year value in ret and length of year value in temp:
           temp = SendMessage(cboYearHwnd, CB_GETLBTEXT, yearIndex, _
               ByVal ret)
           ' uncomment the line below to see if the ComboBox was used:
           'If Calendar1.Year = 0 Then Debug.Print "ComboBox used to
           'select ";
           Debug.Print Left(ret, temp) 'Displays Year
        End Sub

5. Press the CTRL+G key combination to view the Immediate Window.

6. Press the F5 key to run the project.

7. Choose a month from the first combo box. Note the Immediate Window displays
  the month name selected.

8. Choose a year from the second combo box. Note the Immediate Window displays
  the year selected.

NOTE: The NewMonth event can occur either by using the ComboBox to select a new
month or by clicking a new day that is in a different month than the one
currently shown.

For example, suppose the current value in the Calendar is February 1. If you
click on what would be the 31st day, the NewMonth event occurs because you have
chosen a day in January. If you need to distinguish between using the ComboBox
to select a month versus clicking a day in the calendar that changes the month,
check the Month property of the calendar in the NewMonth event. If Month is 0,
the ComboBox was used to select the new month. Otherwise, if Month is greater
than 0, the user chooses a new date in the Calendar. Similarly, you can check
the Year property in the NewYear event.

REFERENCES
==========


Additional query words: kbVBp kbVBp500 kbVBp600 kbCtrl kbdsd kbDSupport

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600
Version           : WINDOWS:5.0,6.0
Issue type        : kbhowto

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