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C#

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

Chilkat C# Downloads

C#
bool success = false;

Chilkat.Zip zip = new Chilkat.Zip();

// Open an existing ZIP archive.
success = zip.OpenZip("qa_data/zips/documents.zip");
if (success == false) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

// Locate the PDF entry within the ZIP archive.
Chilkat.ZipEntry entry = new Chilkat.ZipEntry();

success = zip.EntryOf("docs/report.pdf",entry);
if (success == false) {
    Debug.WriteLine("ZIP entry not found.");
    zip.CloseZip();
    return;
}

// ------------------------------------------------------------
// Inflate the ZIP entry directly into a BinData object.
// 
// The uncompressed bytes are stored entirely in memory.
// 
Chilkat.BinData pdfData = new Chilkat.BinData();

success = entry.UnzipToBd(pdfData);
if (success == false) {
    Debug.WriteLine(entry.LastErrorText);
    return;
}

Debug.WriteLine("Uncompressed size = " + Convert.ToString(pdfData.NumBytes));
Debug.WriteLine("");

// ------------------------------------------------------------
// Optionally save the uncompressed bytes to a file.
// 
success = pdfData.WriteFile("qa_output/report.pdf");
if (success == false) {
    Debug.WriteLine(pdfData.LastErrorText);
    return;
}

zip.CloseZip();

Debug.WriteLine("PDF extracted successfully.");