NdisUnmapFile function (ndis.h)

Article
02/22/2024

The NdisUnmapFile function releases a virtual address mapping of a file previously set up with the NdisMapFile function.

Syntax

void NdisUnmapFile(
  [in] NDIS_HANDLE FileHandle
);

Parameters

[in] FileHandle

The handle that was returned by the NdisOpenFile function.

Return value

None

Remarks

To reduce resource usage, a miniport driver should always call NdisUnmapFile when it no longer needs exclusive access to the contents of a file that it opened. Such a driver can map and unmap the file as necessary, using alternating calls to NdisMapFile and NdisUnmapFile until it releases the file handle with the NdisCloseFile function.

Requirements

Requirement	Value
Minimum supported client	Supported for NDIS 6.0 and NDIS 5.1 drivers (see NdisUnmapFile (NDIS 5.1)) in Windows Vista. Supported for NDIS 5.1 drivers (see NdisUnmapFile (NDIS 5.1)) in Windows XP.
Target Platform	Universal
Header	ndis.h (include Ndis.h)
Library	Ndis.lib
IRQL	PASSIVE_LEVEL
DDI compliance rules	Irql_Miscellaneous_Function(ndis)