VB.NET

Unzip a ZIP Entry Directly into a BinData Object Using ZipEntry.UnzipToBd

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This example demonstrates how to use the ZipEntry.UnzipToBd method to inflate a ZIP entry directly into a BinData object.

The entry contents are uncompressed entirely in memory without creating a file on disk.

This is useful when:

• Processing ZIP entry data entirely in memory
• Avoiding temporary filesystem files
• Working with binary files such as images, PDFs, or certificates
• Passing uncompressed ZIP data directly to other APIs

The example opens a ZIP archive, locates a PDF entry, inflates it into a BinData object, and then writes the uncompressed bytes to a new file.

Suppose the ZIP archive contains:

docs/report.pdf

The entry is uncompressed directly into memory before optionally being saved to:

qa_output/report.pdf

VB.NET

Dim success As Boolean = False

Dim zip As New Chilkat.Zip

' Open an existing ZIP archive.
success = zip.OpenZip("qa_data/zips/documents.zip")
If (success = False) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


' Locate the PDF entry within the ZIP archive.
Dim entry As New Chilkat.ZipEntry

success = zip.EntryOf("docs/report.pdf",entry)
If (success = False) Then
    Debug.WriteLine("ZIP entry not found.")
    zip.CloseZip()
    Exit Sub
End If


' ------------------------------------------------------------
' Inflate the ZIP entry directly into a BinData object.
' 
' The uncompressed bytes are stored entirely in memory.
' 
Dim pdfData As New Chilkat.BinData

success = entry.UnzipToBd(pdfData)
If (success = False) Then
    Debug.WriteLine(entry.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Uncompressed size = " & pdfData.NumBytes)
Debug.WriteLine("")

' ------------------------------------------------------------
' Optionally save the uncompressed bytes to a file.
' 
success = pdfData.WriteFile("qa_output/report.pdf")
If (success = False) Then
    Debug.WriteLine(pdfData.LastErrorText)
    Exit Sub
End If


zip.CloseZip()

Debug.WriteLine("PDF extracted successfully.")