Last modified: July 23, 2011
Applies to: Outlook
Describes a combo box control that will be used in a dialog box built from a display table.
A DTBLCOMBOBOX structure describes a combo box a control that consists of a list and a selection field. The list presents the information from which a user can select, and the selection field displays the current selection. The selection field is an edit control that can also be used to enter text not already in the list.
The two property tag members work together to coordinate the list display with the edit control. When MAPI first displays the combo box, it calls the OpenProperty method of the IMAPIProp implementation that is associated with the display table to retrieve the table represented by the ulPRTableName member. This table has one column a column that contains values for the property represented by the ulPRPropertyName member. Therefore, this column must be of the same type as the ulPRPropertyName property and both columns must be character strings.
The values for the column are displayed in the list section of the combo box. Therefore, PR_NULL (PidTagNull) is not a valid property tag for ulPRPropertyName. When a user either selects one of the rows or enters new data into the text box, the ulPRPropertyName property is set to the selected or entered value.
To display an initial value for the edit control, MAPI calls IMAPIProp::GetProps to retrieve the property values for the display table. If one of the retrieved properties matches the property represented by the ulPRPropertyName member, its value becomes the initial value.