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LOCKTYPE enumeration (objidl.h)

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The LOCKTYPE enumeration values indicate the type of locking requested for the specified range of bytes. The values are used in the ILockBytes::LockRegion and IStream::LockRegion methods.

Syntax

typedef enum tagLOCKTYPE {
  LOCK_WRITE = 1,
  LOCK_EXCLUSIVE = 2,
  LOCK_ONLYONCE = 4
} LOCKTYPE;

Constants

 
LOCK_WRITE
Value: 1
If this lock is granted, the specified range of bytes can be opened and read any number of times, but writing to the locked range is prohibited except for the owner that was granted this lock.
LOCK_EXCLUSIVE
Value: 2
If this lock is granted, writing to the specified range of bytes is prohibited except by the owner that was granted this lock.
LOCK_ONLYONCE
Value: 4
If this lock is granted, no other LOCK_ONLYONCE lock can be obtained on the range. Usually this lock type is an alias for some other lock type. Thus, specific implementations can have additional behavior associated with this lock type.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header objidl.h