ACX_REQUEST_PARAMETERS_INIT_PROPERTY function (acxrequest.h)

Article
02/22/2024

The ACX_REQUEST_PARAMETERS_INIT_PROPERTY initializes an ACX_REQUEST_PARAMETERS struct with ACX property parameters.

Syntax

void ACX_REQUEST_PARAMETERS_INIT_PROPERTY(
  PACX_REQUEST_PARAMETERS Params,
  const GUID              Set,
  ULONG                   Id,
  ACX_PROPERTY_VERB       Verb,
  ACX_ITEM_TYPE           ItemType,
  ULONG                   ItemId,
  PVOID                   Control,
  ULONG                   ControlCb,
  PVOID                   Value,
  ULONG                   ValueCb
);

Parameters

Params

A pointer to ACX_REQUEST_PARAMETERS structure that is used to store property parameters.

Set

A property Set ID (GUID).

Id

A property ID (ULONG) within the property Set ID.

Verb

The ACX property verb to send as defined by the ACX_PROPERTY_VERB enumeration.

ItemType

The ACX_ITEM_TYPE type of item being sent, for example AcxItemTypeCircuit.

ItemId

The item ID of the ItemType, for example the pin ID if the ItemType is a pin.

Control

An optional Control buffer holding additional parameters for the specified property. Set to null if not present.

ControlCb

The count in bytes (size) of the Control buffer. Set to 0 if Control field is not used.

Value

An optional Value buffer to specify or receive the property's value. Set to null if not present or if *SendProperty needs to allocate it when ValueCb is not zero. Caller is responsible for freeing the allocated buffer.

ValueCb

The count in bytes (size) of the Value buffer. Set to 0 if Value is not used.

Return value

None

Remarks

Example

Example usage is shown below.


    NTSTATUS                    status = STATUS_SUCCESS;
    PKSPIN_PHYSICALCONNECTION   physicalConnection = nullptr;
    PAUDIO_PATH_DESCRIPTOR      descriptor = nullptr;

    // For the Audio Circuit, send a request to each Target Pin asking KSPROPERTY_PIN_PHYSICALCONNECTION
    // This will give us symbolic link of the next circuit in the Audio Path (if there is any)

    for (ULONG i = 0; i < ARRAYSIZE(AudioCircuit->Pins) && AudioCircuit->Pins[i].TargetPin; ++i)
    {
        ACX_REQUEST_PARAMETERS requestParams{ 0 };

        ACX_REQUEST_PARAMETERS_INIT_PROPERTY(
            &requestParams,
            KSPROPSETID_Pin,
            KSPROPERTY_PIN_PHYSICALCONNECTION,
            AcxPropertyVerbGet,
            AcxItemTypePin,
            i,
            nullptr,
            0,
            // null Value so SendProperty will allocate it for us. We'll need to free it.
            nullptr,
            0);
...

ACX requirements

Minimum ACX version: 1.0

For more information about ACX versions, see ACX version overview.

Requirements

Requirement	Value
Header	acxrequest.h

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