B4X

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

B4X

Dim success As Boolean = False

Dim zip As ChilkatZip
zip.Initialize("zip")

'  Open an existing ZIP archive.
success = zip.OpenZip("qa_data/zips/documents.zip")
If success = False Then
    Log(zip.LastErrorText)
    Return
End If


'  Locate the PDF entry within the ZIP archive.
Dim entry As ChilkatZipEntry
entry.Initialize("entry")

success = zip.EntryOf("docs/report.pdf", entry)
If success = False Then
    Log("ZIP entry not found.")
    zip.CloseZip
    Return
End If


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

success = entry.UnzipToBd(pdfData)
If success = False Then
    Log(entry.LastErrorText)
    Return
End If


Log("Uncompressed size = " & pdfData.NumBytes)
Log("")

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


zip.CloseZip

Log("PDF extracted successfully.")