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TcQueryFlowW function (traffic.h)

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The TcQueryFlow function queries traffic control for the value of a specific flow parameter based on the name of the flow. The name of a flow can be retrieved from the TcEnumerateFlows function or from the TcGetFlowName function.

Syntax

ULONG TcQueryFlowW(
  [in]      LPWSTR pFlowName,
  [in]      LPGUID pGuidParam,
  [in, out] PULONG pBufferSize,
  [out]     PVOID  Buffer
);

Parameters

[in] pFlowName

Name of the flow being queried.

[in] pGuidParam

Pointer to the globally unique identifier (GUID) that corresponds to the flow parameter of interest. A list of traffic control's GUIDs can be found in GUID.

[in, out] pBufferSize

Pointer to the size of the client-provided buffer or the number of bytes used by traffic control. For input, points to the size of Buffer, in bytes. For output, points to the actual amount of buffer space written with returned flow-parameter data, in bytes.

[out] Buffer

Pointer to the client-provided buffer in which the returned flow parameter is written.

Return value

Return code Description
NO_ERROR
 The function executed without errors.
ERROR_INVALID_PARAMETER
 A parameter is invalid.
ERROR_INSUFFICIENT_BUFFER
 The provided buffer is too small to hold the results.
ERROR_NOT_SUPPORTED
 The requested GUID is not supported.
ERROR_WMI_GUID_NOT_FOUND
 The device did not register for this GUID.
ERROR_WMI_INSTANCE_NOT_FOUND
 The instance name was not found, likely because the flow or the interface is in the process of being closed.

Remarks

Use of the TcQueryFlow function requires administrative privilege.

Note

The traffic.h header defines TcQueryFlow as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header traffic.h
DLL Traffic.dll

See also

GUID

TcEnumerateFlows

TcGetFlowName