DownloadFileInBlocks_ReadBlock Method

The number of bytes to be read. For the download session to be closed, the combined size of the blocks must exceed the actual size of the file. The block size should not be more than 4MB (4,194,304). Before M-Files 23.3, using a block size of larger than 4MB may cause unexpected behavior, including exceptions, depending upon the underlying storage. From M-Files 23.3, M-Files will throw an exception if the block size is larger than 4MB.

Description

Retrieves a specific block of the specified file from the server.

Syntax

Visual Basic
Public Function DownloadFileInBlocks_ReadBlock( _ ByVal DownloadID As Long, _ ByVal BlockSize As Long, _ ByVal Offset As Unknown _ ) As Byte()

Visual Basic

Public Function DownloadFileInBlocks_ReadBlock( _
   ByVal DownloadID As Long, _
   ByVal BlockSize As Long, _
   ByVal Offset As Unknown _
) As Byte()

Parameters

DownloadID: The identifier of the download operation returned by DownloadFileInBlocks_Begin.
BlockSize: The number of bytes to be read. For the download session to be closed, the combined size of the blocks must exceed the actual size of the file. The block size should not be more than 4MB (4,194,304). Before M-Files 23.3, using a block size of larger than 4MB may cause unexpected behavior, including exceptions, depending upon the underlying storage. From M-Files 23.3, M-Files will throw an exception if the block size is larger than 4MB.
Offset: The byte offset from the beginning of the file as a 64-bit integer.

Remarks

For the download session to be closed, the combined size of the blocks must exceed the actual size of the file.
This method is available only if M-Files API is used in the server interface mode.
This method requires support for 64-bit data types. Use DownloadFileInBlocks_ReadBlock_32bit in development environments that do not support these data types such as VBScript.
- Development environment should not be confused with the operating system: This method can be used in 32-bit operating systems.