How to Employ the Verb Selection Model
Registry values must be set for verbs to handle situations where a user can select a single item, multiple items, or a selection from an item. A verb requires separate registry values for each of these three situations that the verb supports.
Specify the MultiSelectModel value for all verbs. If the MultiSelectModel value is not specified, it is inferred from the type of verb implementation you have chosen. For COM-based methods (such as DropTarget and ExecuteCommand) Player is assumed, and for the other methods Document is assumed.
The possible values for the verb selection model are as follows:
- Specify Single for verbs that support only a single selection.
- Specify Player for verbs that support any number of items.
- Specify Document for verbs that create a top-level window for each item. Doing so limits the number of items that are activated and helps avoid running out of system resources if the user opens too many windows.
When the number of items selected does not match the verb selection model or is greater than the default limits outlined in the following table, the verb fails to appear.
|Type of verb implementation||Document||Player|
|Legacy||15 items||100 items|
|COM||15 items||No limit|
The following are example registry entries that use the MultiSelectModel value.
HKEY_CLASSES_ROOT Folder shell open = MultiSelectModel = Document
HKEY_CLASSES_ROOT ProgID shell verb = MultiSelectModel = Single | Document | Player