IRunningObjectTable:IUnknown (Windows CE 5.0)

Artigo
09/14/2012

This interface manages access to the Running Object Table (ROT), a globally accessible look-up table on each workstation. A workstation's ROT keeps track of those objects that can be identified by a moniker and that are currently running on the workstation.

When a client tries to bind a moniker to an object, the moniker checks the ROT to see if the object is already running; this allows the moniker to bind to the current instance instead of loading a new one.

The ROT contains entries of the form shown in the following code example.

(pmkObjectName, pUnkObject)

The pmkObjectName element is a pointer to the moniker that identifies the running object. The pUnkObject element is a pointer to the running object itself. During the binding process, monikers consult the pmkObjectName entries in the Running Object Table to see if an object is already running.

Objects that can be named by monikers must be registered with the ROT when they are loaded and their registration must be revoked when they are no longer running.

When to Implement

You do not need to implement this interface. The system provides an implementation of the Running Object Table that is suitable for all situations.

When to Use

You typically use the ROT if you are a moniker provider (that is, you hand out monikers identifying your objects to make them accessible to others) or if you are writing your own moniker class (that is, implementing the IMoniker interface).

If you are a moniker provider, you register your objects with the ROT when they begin running and revoke their registrations when they are no longer running. This enables the monikers that you hand out to be bound to running objects.

You should also use the ROT to record the object's last modification time. You can get an IRunningObjectTable interface pointer to the local ROT by calling the GetRunningObjectTable function.

The most common type of moniker provider is a compound-document link source. This includes server applications that support linking to their documents (or portions of a document) and container applications that support linking to embeddings within their documents.

Server applications that do not support linking can also use the ROT to cooperate with container applications that support linking to embeddings.

If you are writing your own moniker class, you use the ROT to determine whether a object is running and to retrieve the object's last modification time.

You can get an IRunningObjectTable interface pointer to the local ROT by calling the IBindCtx::GetRunningObjectTable method on the bind context for the current binding operation.

Moniker implementations should always use the bind context to acquire a pointer to the ROT; this allows future implementations of IBindCtx to modify binding behavior.

You must implement the IROTData interface on your moniker class in order to allow your monikers to be registered with the ROT.

Methods in Vtable Order

IUnknown method	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.

Method	Description
Register	Registers an object with the ROT.
Revoke	Revokes an object's registration with the ROT.
IsRunning	Checks whether an object is running.
GetObject	Returns a pointer to an object given its moniker.
NoteChangeTime	Notifies the ROT that an object has changed.
GetTimeOfLastChange	Returns the time an object was last changed.
EnumRunning	Returns an enumerator for the ROT.

Remarks

To determine whether the platform supports this interface, see Determining Supported COM APIs.

Requirements

OS Versions: Windows CE 3.0 and later.
Header: Objidl.h, Objidl.idl.
Link Library: Ole32.lib, Uuid.lib.

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