Interface ILockBytes

Summary description for ILockBytes.

Namespace: Syncfusion.CompoundFile.XlsIO.Native

Assembly: Syncfusion.XlsIO.Base.dll

Syntax

[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("0000000a-0000-0000-C000-000000000046")]
[CLSCompliant(false)]
public interface ILockBytes

Methods

Flush()

The Flush method ensures that any internal buffers maintained by the ILockBytes implementation are written out to the underlying physical storage.

Declaration

int Flush()

Returns

Type	Description
System.Int32	S_OK - The flush operation was successful. STG_E_ACCESSDENIED - The caller does not have permission to access the byte array. STG_E_MEDIUMFULL - The flush operation is not completed because there is no space left on the storage device. E_FAIL - General failure writing data. STG_E_TOOMANYFILESOPEN - Under certain circumstances, the Flush method executes a download-and-closeto flush, which can lead to a return value of STG_E_TOOMANYFILESOPEN if no file handles are available. STG_E_INVALIDHANDLE - An underlying file has been prematurely closed, or the correct floppy disk has been replaced by an invalid one.

LockRegion(UInt64, UInt64, UInt32)

The LockRegion method restricts access to a specified range of bytes in the byte array.

Declaration

int LockRegion(ulong libOffset, ulong cb, uint dwLockType)

Parameters

Type	Name	Description
System.UInt64	libOffset	Specifies the byte offset for the beginning of the range.
System.UInt64	cb	Specifies, in bytes, the length of the range to be restricted.
System.UInt32	dwLockType	Specifies the type of restrictions being requested on accessing the range. This parameter uses one of the values from the LOCKTYPE enumeration.

Returns

Type	Description
System.Int32	S_OK - The specified range of bytes was locked STG_E_INVALIDFUNCTION - Locking is not supported at all or the specific type of lock requested is not supported. STG_E_ACCESSDENIED - Access denied because the caller has insufficient permission, or another caller has the file open and locked. STG_E_LOCKVIOLATION - Access denied because another caller has the file open and locked. STG_E_INVALIDHANDLE - An underlying file has been prematurely closed, or the correct floppy disk has been replaced by an invalid one

ReadAt(UInt64, Byte[], UInt32, out UInt32)

The ReadAt method reads a specified number of bytes starting at a specified offset from the beginning of the byte array object.

Declaration

int ReadAt(ulong ulOffset, byte[] pv, uint cb, out uint pcbRead)

Parameters

Type	Name	Description
System.UInt64	ulOffset	Specifies the starting point from the beginning of the byte array for reading data.
System.Byte[]	pv	Pointer to the buffer into which the byte array is read. The size of this buffer is contained in cb.
System.UInt32	cb	Specifies the number of bytes of data to attempt to read from the byte array.
System.UInt32	pcbRead	Pointer to a ULONG where this method writes the actual number of bytes read from the byte array. You can set this pointer to NULL to indicate that you are not interested in this value. In this case, this method does not provide the actual number of bytes that were read.

Returns

Type	Description
System.Int32	S_OK - Indicates that the specified number of bytes were read, or the maximum number of bytes were read to the end of the byte array. E_FAIL - Data could not be read from the byte array. E_PENDING - Asynchronous Storage only: Part or all of the data to be read is currently unavailable. STG_E_ACCESSDENIED - The caller does not have permission to access the byte array. STG_E_READFAULT - The number of bytes to be read does not equal the number of bytes that were actually read

SetSize(UInt64)

The SetSize method changes the size of the byte array.

Declaration

int SetSize(ulong cb)

Parameters

Type	Name	Description
System.UInt64	cb	Specifies the new size of the byte array as a number of bytes.

Returns

Type	Description
System.Int32	S_OK - The size of the byte array was successfully changed. STG_E_ACCESSDENIED - The caller does not have permission to access the byte array. STG_E_MEDIUMFULL - The byte array size is not changed because there is no space left on the storage device.

Stat(out STATSTG, UInt32)

The Stat method retrieves a STATSTG structure containing information for this byte array object.

Declaration

int Stat(out STATSTG pstatstg, uint grfStatFlag)

Parameters

Type	Name	Description
STATSTG	pstatstg	Pointer to a STATSTG structure in which this method places information about this byte array object. The pointer is NULL if an error occurs.
System.UInt32	grfStatFlag	Specifies whether this method should supply the pwcsName member of the STATSTG structure through values taken from the STATFLAG enumeration. If the STATFLAG_NONAME is specified, the pwcsName member of STATSTG is not supplied, thus saving a memory-allocation operation. The other possible value, STATFLAG_DEFAULT, indicates that all members of the STATSTG structure be supplied.

Returns

Type	Description
System.Int32	S_OK - The STATSTG structure was successfully returned at the specified location. E_OUTOFMEMORY - The STATSTG structure was not returned due to a lack of memory for the name member in the structure. STG_E_ACCESSDENIED - The STATSTG structure was not returned because the caller did not have access to the byte array. STG_E_INSUFFICIENTMEMORY - The STATSTG structure was not returned, due to insufficient memory. STG_E_INVALIDFLAG - The value for the grfStateFlag parameter is not valid. STG_E_INVALIDPOINTER - The value for the pStatStg parameter is not valid.

UnlockRegion(UInt64, UInt64, UInt32)

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

Declaration

int UnlockRegion(ulong libOffset, ulong cb, uint dwLockType)

Parameters

Type	Name	Description
System.UInt64	libOffset	Specifies the byte offset for the beginning of the range.
System.UInt64	cb	Specifies, in bytes, the length of the range that is restricted.
System.UInt32	dwLockType	Specifies the type of access restrictions previously placed on the range. This parameter uses a value from the LOCKTYPE enumeration.

Returns

Type	Description
System.Int32	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.

WriteAt(UInt64, Byte[], UInt32, out UInt32)

The WriteAt method writes the specified number of bytes starting at a specified offset from the beginning of the byte array.

Declaration

int WriteAt(ulong ulOffset, byte[] pv, uint cb, out uint pcbWritten)

Parameters

Type	Name	Description
System.UInt64	ulOffset	Specifies the starting point from the beginning of the byte array for the data to be written.
System.Byte[]	pv	Pointer to the buffer containing the data to be written.
System.UInt32	cb	Specifies the number of bytes of data to attempt to write into the byte array.
System.UInt32	pcbWritten	Pointer to a location where this method specifies the actual number of bytes written to the byte array. You can set this pointer to NULL to indicate that you are not interested in this value. In this case, this method does not provide the actual number of bytes written.

Returns

Type	Description
System.Int32	S_OK - Indicates that the specified number of bytes were written. E_FAIL - A general failure occurred during the write operation. E_PENDING - Asynchronous Storage only: Part or all of the data to be written is currently unavailable. STG_E_ACCESSDENIED - The caller does not have enough permissions for writing this byte array. STG_E_WRITEFAULT - The number of bytes to be written does not equal the number of bytes that were actually written. STG_E_MEDIUMFULL - The write operation was not completed because there is no space left on the storage device. The actual number of bytes written is still returned in pcbWritten.