ILockBytes::UnlockRegion method (objidl.h)

Article
02/22/2024

The UnlockRegion method removes the access restriction on a previously locked range of bytes.

Syntax

HRESULT UnlockRegion(
  [in] ULARGE_INTEGER libOffset,
  [in] ULARGE_INTEGER cb,
  [in] DWORD          dwLockType
);

Parameters

[in] libOffset

Specifies the byte offset for the beginning of the range.

[in] cb

Specifies, in bytes, the length of the range that is restricted.

[in] dwLockType

Specifies the type of access restrictions previously placed on the range. This parameter uses a value from the LOCKTYPE enumeration.

Return value

This method can return one of these values.

Return code	Description
S_OK	The byte range was unlocked.
STG_E_INVALIDFUNCTION	Locking is not supported at all or the specific type of lock requested is not supported.
STG_E_LOCKVIOLATION	The requested unlock cannot be granted.

Remarks

ILockBytes::UnlockRegion unlocks a region previously locked with a call to ILockBytes::LockRegion. Each region locked must be explicitly unlocked, using the same values for the libOffset, cb, and dwLockType parameters as in the matching calls to ILockBytes::LockRegion. Two adjacent regions cannot be locked separately and then unlocked with a single unlock call.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	objidl.h
Library	Uuid.lib
DLL	Ole32.dll