Microsoft KB Archive/292457

= OL2002: How to Properly Reference Members of a Collection =

Article ID: 292457

Article Last Modified on 11/23/2006

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APPLIES TO


 * Microsoft Outlook 2002 Standard Edition

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This article was previously published under Q292457





SUMMARY
If you use Visual Basic, Visual Basic for Applications, or Visual Basic Scripting Edition (VBScript) to loop through items in a folder, you may see the modifications to those items are not saved. You may be unintentionally retrieving the item again from the Items collection, and any changes that you have made to an item are unexpectedly lost.



MORE INFORMATION
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http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

Many Outlook solutions modify the contents of items in a folder. In most scenarios you loop through the Items collection in the Outlook object model. If you do not properly reference the items in the collection, you may receive unexpected results.

Before modifying an item and saving it, you should set an object variable to the item, make changes to the item using the object variable, and then save the object.

NOTE: Be sure to reference the Microsoft Outlook 10.0 Object Library before running these code examples and be aware running this code will modify any existing contacts you have in your Contacts folder.

Consider the following Visual Basic automation code sample that is designed to reset the birthday field for each contact in the default Contacts folder: Sub ResetBirthdays1 Dim olns as Outlook.Namespace Dim oConItems As Outlook.Items Dim iNumItems As Integer Set ol = New Outlook.Application Set olns = ol.GetNamespace(&quot;MAPI&quot;) Set oConItems = olns.GetDefaultFolder(olFolderContacts).Items iNumItems = oConItems.Count For I = 1 to iNumItems oConItems.Item(I).Birthday = &quot;1/1/4501&quot; oConItems.Item(I).Close olSave Next Set oConItems = Nothing Set olns = Nothing Set ol = Nothing End Sub In the previous example, the loop is adequately structured and will process all of the items in the folder. However, within the loop each time ConItems.Item(I) is executed, it retrieves the specific item from the collection of items. In this case, the Birthday is set for an item, but then then following line of code gets the item from the collection again. The end result is that an unmodified item is saved.

The following example is one way of modifying the previous code sample so that it executes as expected: Sub ResetBirthdays2 Dim olns As Outlook.Namespace Dim oConItems As Outlook.Items Dim iNumItems As Integer Set ol = New Outlook.Application Set olns = ol.GetNamespace(&quot;MAPI&quot;) Set oConItems = olns.GetDefaultFolder(olFolderContacts).Items iNumItems = oConItems.Count For I = 1 to iNumItems Set oCurItem = oConItems.Item(I) oCurItem.Birthday = &quot;1/1/4501&quot; oCurItem.Close olSave Next Set oConItems = Nothing Set olns = Nothing Set ol = Nothing End Sub In the previous sample, oCurItem is set to a specific item in the collection, modifications to the item are made using that object variable, and the object is saved. This avoids getting an item from the collection and losing any changes.

The following example provides the same functionality as the previous example, but uses the For Each...Next structure to loop through the items: Sub ResetBirthdays3 Dim olns as Outlook.Namespace Dim oConItems As Outlook.Items Set ol = New Outlook.Application Set olns = ol.GetNamespace(&quot;MAPI&quot;) Set oConItems = olns.GetDefaultFolder(olFolderContacts).Items For Each oCurItem in oConItems oCurItem.Birthday = &quot;1/1/4501&quot; oCurItem.Close olSave Next Set oConItems = Nothing Set olns = Nothing Set ol = Nothing End Sub

