Microsoft KB Archive/170991

= OL97: Programming With EntryIDs, StoreIDs, and GetItemFromID =

Article ID: 170991

Article Last Modified on 2/12/2007

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APPLIES TO


 * Microsoft Outlook 97 Standard Edition

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This article was previously published under Q170991





SUMMARY
This article provides an example of using the GetItemFromID method in the Microsoft Outlook 97 object model.



MORE INFORMATION
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A common use of the GetItemFromID method is to create a link, or relationship, from one Outlook item to another. The Outlook Visual Basic Help file (Vbaoutl.hlp) documents this method.

For more information on obtaining the Outlook Visual Basic Help file, please see the following article in the Microsoft Knowledge Base:

166738 OL97: How to Install Visual Basic Help

An example of when you might want to use the GetItemFromID method is if you created contact items for all members of a family instead of just having one contact item for the head of the household. You might want to create a custom contact form so that you can create "links" between all members of the family. This could be in the form of a list box on the custom contact form that would automatically include a list of other members of the family. Using the custom form, when you select a person from the list, their contact item would automatically display.

In a solution like this, you would typically create the links between the contact items by storing the related IDs with each contact. So each contact item might have 20 user-defined fields that store the IDs of up to 20 related contacts. VBScript code uses these IDs to retrieve the names of the other family members in order to populate the list and to retrieve the other contact item when the user selects a name from the list.

Each Outlook item (contacts, messages, appointments, and such) has a field called EntryID, which is a unique ID field generated by the messaging storage system for use with the MAPI folders which store the item.

Each MAPI folder has a field called StoreID, a unique ID field for that particular folder. Each folder also has an EntryID field.

When using the GetItemFromID method to retrieve an item based on its MAPI IDs, you need to specify both the EntryID of the item and the StoreID of the folder. Using the EntryID of the folder instead of the StoreID will generate an error, which may vary depending on the type of folder you are working with.

The following is a VBScript example which illustrates the use of the GetItemFromID method. The code retrieves the StoreID from the default Contacts folder, fills an array with the EntryIDs for all of the contacts in the folder, and finally retrieves a specific contact item. Sub OutlookEntryID 'The Outlook object library must be referenced Dim ol As Outlook.Application Dim olns As NameSpace Dim objFolder As Object Dim AllContacts As Object Dim Item As Object Dim I As Integer 'If there are more than 500 contacts, change the following line: Dim EntryID(500) As String Dim StoreID As String Dim strFind As String ' Set the application object Set ol = New Outlook.Application ' Set the namespace object Set olns = ol.GetNamespace("MAPI") ' Set the default Contacts folder Set objFolder = olns.GetDefaultFolder(olFolderContacts) ' Get the StoreID, which is a property of the folder StoreID = objFolder.StoreID ' Set objAllContacts = the collection of all contacts Set AllContacts = objFolder.Items I = 0 ' Loop to get all of the EntryIDs for the contacts For Each Item In AllContacts I = I + 1 ' The EntryID is a property of the item EntryID(I) = Item.EntryID Next ' Randomly choose the 2nd Contact to retrieve ' In a larger solution, this might be the index from a listbox I = 2 ' Both the StoreID and EntryID must be used to retrieve the item Set Item = olns.GetItemFromID(EntryID(I), StoreID) Item.Display End Sub

