IPart::EnumPartsOutgoing method (devicetopology.h)

Article
02/22/2024

The EnumPartsOutgoing method retrieves a list of all the outgoing parts—that is, the parts that reside on data paths that are downstream from this part.

Syntax

HRESULT EnumPartsOutgoing(
  [out] IPartsList **ppParts
);

Parameters

[out] ppParts

Pointer to a pointer variable into which the method writes the address of an IPartsList interface that encapsulates the list of parts that are immediately downstream from this part. Through this method, the caller obtains a counted reference to the interface. The caller is responsible for releasing the interface, when it is no longer needed, by calling the interface's Release method. If the EnumPartsOutgoing call fails, *ppParts is NULL.

Return value

If the method succeeds, it returns S_OK. If it fails, possible return codes include, but are not limited to, the values shown in the following table.

Return code	Description
E_POINTER	Pointer ppParts is NULL.
E_NOTFOUND	This part has no links to downstream parts.
E_OUTOFMEMORY	Out of memory.

Remarks

A client application can traverse a device topology in the direction of audio data flow by iteratively calling this method at each step in the traversal to get the list of parts that lie immediately downstream from the current part.

If this part has no links to downstream parts, the method returns error code E_NOTFOUND and does not create a parts list (*ppParts is NULL). For example, the method returns this error code if the IPart interface represents a connector through which data exits a device topology.

For a code example that uses the EnumPartsOutgoing method, see the implementation of the SelectCaptureDevice function in Device Topologies.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Target Platform	Windows
Header	devicetopology.h