Extending the Taskpad of a Primary Snap-in

This section discusses the specific Steps necessary for an extension snap-in to extend the taskpad of an extendable node type owned by a primary snap-in. For more information about working with snap-ins, see Working with Extension Snap-ins.

A primary snap-in registers the extendable node types that it adds to its namespace. An extension snap-in can extend the taskpad of a primary snap-in's node type by adding the appropriate registration code and then implementing the IExtendTaskPad and IEnumTASK interfaces. The snap-in extends a node type's taskpad by adding additional tasks to it.

A taskpad extension can optionally support IComponentData. If it does, it gains two features of namespace extensions:

  • When created, the taskpad extension remains loaded for the duration of the MMC session.
  • The taskpad extension can persist data in the console file by implementing IPersistStream. For more information, see Snap-in Persistence Model.

Be aware that if the extension snap-in must create its own taskpad, rather than use a primary snap-in's taskpad, it should be a namespace extension instead. As a namespace extension, it can add a scope item to a primary snap-in's scope pane and create a taskpad view for that item. For more information about namespace extensions, see Extending a Primary Snap-in's Namespace.

In the following procedure, be aware that {CLSID}, {snapinCLSID}, and {nodetypeGUID} all denote string representations of the specified CLSIDs and GUIDs. The strings must begin with an open brace ({) and end with a close brace (}).

Aa814677.wedge(en-us,VS.85).gifTo extend the taskpad of a primary snap-in

  1. The CLSID of each snap-in (extension or stand-alone) must be registered under the HKEY_CLASSES_ROOT\CLSID key in the {CLSID} subkey as an in-process server DLL. The snap-in must also register a threading model for the snap-in CLSID. An apartment threading model is recommended.

    For more information about the HKEY_CLASSES_ROOT\CLSID key, see the CLSID Key. For more information and a code example, see Registering and Unregistering a Snap-in.

  2. All snap-ins must be registered under the HKEY_LOCAL_MACHINE\Software\Microsoft\MMC\SnapIns key in the {snapinCLSID} key. For more information about the SnapIns key, see Registering and Unregistering a Snap-in.
  3. Register the CLSID of the extension snap-in under the HKEY_LOCAL_MACHINE\Software\Microsoft\MMC\NodeTypes\{nodetypeGUID}\Extensions\Task subkey, where nodetypeGUID is the node type GUID of the node type whose taskpad is extended. For more information about the NodeTypes key, see Registration Requirements for Extension Snap-ins.
  4. Implement the IExtendTaskPad and IEnumTASK interfaces. The only IExtendTaskPad interface methods you must implement are EnumTasks and TaskNotify. All other methods can return E_NOTIMPL. The extension's EnumTasks implementation is used by MMC to get a pointer to the extension's IEnumTASK interface. The TaskNotify method is used for sending notifications from the taskpad to the extension when one of the extension's tasks is clicked. Be aware that the primary snap-in that owns the scope item that is that displays the taskpad is responsible for loading the taskpad template and setting up the taskpad through its own IExtendTaskPad methods.
  5. If the taskpad extension persists data in the console file, the snap-in must implement IComponentData. As a result of implementing IComponentData, when loaded, the taskpad extension remains loaded for the duration of the current MMC session. Also, the extension object must expose the snap-in IComponentData and IExtendTaskPad interfaces.

Related topics

Using Taskpads
Working with Extension Snap-ins