DOCUMENT:Q159426  12-APR-1999  [exchange]
TITLE   :XCLN: How to Write Listbox Items to an E-form Package
PRODUCT :Microsoft Exchange
PROD/VER:WINDOWS:4.0,5.0
OPER/SYS:
KEYWORDS:kbusage

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The information in this article applies to:

 - Microsoft Exchange Windows 95/98 client, versions 4.0, 5.0 
 - Microsoft Exchange Windows 3.x client, versions 4.0, 5.0 
 - Microsoft Exchange Windows NT client, versions 4.0, 5.0 
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SUMMARY
=======

When you use the Microsoft Exchange 4.0 Electronic Forms Designer to create a
custom E-form that has a listbox, you can set the initial content of the listbox
by double-clicking the listbox to open up a Field Properties dialog box,
choosing the Initial Value tab, and setting the list items for the listbox.

But sometimes you may want to have an initially blank listbox and have the E-form
sender dynamically add or remove the list items. In this case, you have to
modify the Visual Basic code generated by the E-form Designer to write the
content of the listbox to the E-form package. Otherwise, the receiver of the
E-form will receive a blank listbox. This article illustrates the techniques of
writing the listbox items to an E-form package.

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

1. Use the Microsoft Exchange E-form Designer Wizard to generate an one- window
   electronic form called List.efp. Add a listbox to the E-form. Compile and
   install the form. This will generate a 16-bit Visual Basic project called
   List.vbp.

2. Load List.vbp into a 16-bit version of Visual Basic.

3. Add a Command button, Command1, to Window1.Frm. In the click event, populate
   the list box:

         Private Sub Command1_Click()
             Dim i As Integer
             For i = 0 To 10
                 ListBox1_Ctrl.AddItem "Item " & i
             Next i
         End Sub

4. Add a public function to Window1.Frm to write the list items of ListBox1_Ctrl
   into a single Visual Basic Variant type variable:

   Public Function CreateVariant() As Variant
             Dim varRet As Variant
             Dim strTemp() As String
             ReDim strTemp(ListBox1_Ctrl.ListCount) As String
             Dim i As Integer
             For i = 0 To ListBox1_Ctrl.ListCount - 1
                 strTemp(i) = ListBox1_Ctrl.List(i)
             Next i
             CreateVariant = strTemp 'store an array into a variant
         End Function

5. Remove the ListBox1_Ctrl_Click() procedure from the Window1.Frm.

6. In the Window_Store procedure of the Window1.Frm, add the following
   statement

         ListBox1_Ctrl_Val = CreateVariant

   before the following statement

         Call SetMapiProp(ctlSubject.Text, "MAPI_Subject_Custom",vbString, Msg)

7. In the Window_Load procedure, comment out the following statement:

         If (VarType(varTemp) And vbArray) = vbArray Then varTemp = varTemp(0)

8. Change the SetListBoxValue subroutine in the Global.bas to the following:

         Public Sub SetListBoxValue(ByVal var As Variant, ctl As Control, _
            inType As Integer)
             Dim Index As Integer
             Dim lstMost As Integer

             If IsNull(var) Then Exit Sub
             If VarType(var) < vbArray Then Exit Sub
             ctl.Clear
             lstMost = UBound(var)
             For Index = 0 To lstMost - 1
                 ctl.AddItem var(Index)
             Next Index

         End Sub

9. Rebuild the executable file and install it.

To test the newly installed E-form , the sender loads the form using the
Microsoft Exchange client. The sender first clicks the Command1 button to
populate the listbox and then click the Send button. When the receiver opens up
the received form, the list items of the listbox are received.


Additional query words: Eforms VB Eform

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Keywords          : kbusage 
Technology        : kbExchangeSearch kbExchange500 kbExchange400 kbExchangeClientSearch kbZNotKeyword kbZNotKeyword2 kbZNotKeyword3 kbExchange400NT kbExchange500NT kbExchange400Win95 kbExchange500Win95
Version           : WINDOWS:4.0,5.0
Issue type        : kbhowto

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