(VB.NET UWP/WinRT) Decompress Large Binary File in Blocks

Decompresses a large binary file in blocks. This example uses BeginDecompressBytes, MoreDecompressBytes, and EndDecompressBytes.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim facSrc As New Chilkat.FileAccess
Dim facDest As New Chilkat.FileAccess

' Open a previously compressed file for decompressing.
' See Compress Large File in Blocks

Dim success As Boolean = facSrc.OpenForRead("qa_data/bmp/compressedBmp.dat")
If (success <> True) Then
    Debug.WriteLine(facSrc.LastErrorText)
    Exit Sub
End If


' If we compress in 32K chunks, find out how many blocks there will be.
Dim blockSize As Integer = 32768
Dim numBlocks As Integer = facSrc.GetNumBlocks(blockSize)

' Open an output file for the decompressed data.
success = facDest.OpenForWrite("qa_output/decompressed.bmp")
If (success <> True) Then
    Debug.WriteLine(facDest.LastErrorText)
    Exit Sub
End If



Dim compress As New Chilkat.Compression
compress.Algorithm = "deflate"

Dim decompressedBytes() As Byte
Dim compressedBytes() As Byte

Dim i As Integer = 0
While i < numBlocks
    compressedBytes = facSrc.ReadBlock(i,blockSize)
    If (i = 0) Then
        decompressedBytes = Await compress.BeginDecompressBytesAsync(compressedBytes)
    Else
        decompressedBytes = Await compress.MoreDecompressBytesAsync(compressedBytes)
    End If


    facDest.FileWrite(decompressedBytes)

    i = i + 1
End While

' At the very end, flush any remaining decompressed bytes, if any.
decompressedBytes = Await compress.EndDecompressBytesAsync()
facDest.FileWrite(decompressedBytes)

facSrc.FileClose()
facDest.FileClose()

Debug.WriteLine("Finished decompressing file.")