(VB.NET) Get Compressed ZIP Entry Data as Base64 Using ZipEntry.CopyToBase64

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This example creates a small ZIP archive containing a text file added from memory, writes the ZIP to disk, re-opens it, and then uses ZipEntry.CopyToBase64 to retrieve the compressed data for the text file as a Base64-encoded string.

The Base64 string returned by CopyToBase64 represents the compressed bytes stored for the entry inside the ZIP archive. It is not the original uncompressed text data.

Note: This example requires Chilkat v11.0.0 or greater.

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Dim success As Boolean = False

' ------------------------------------------------------------
' First create a sample ZIP archive containing a small text file.

Dim zip As New Chilkat.Zip

success = zip.NewZip("c:/temp/sampleText.zip")
If (success = False) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


' Add a small text file from memory.
' The text is stored in the ZIP as "hello.txt".
success = zip.AddString("hello.txt","Hello from a ZIP entry!","utf-8")
If (success = False) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


' Write the ZIP archive to disk and close it.
success = zip.WriteZipAndClose()
If (success = False) Then
    Debug.WriteLine(zip.LastErrorText)
    Exit Sub
End If


' ------------------------------------------------------------
' Now open the ZIP archive we just created.

Dim zip2 As New Chilkat.Zip

success = zip2.OpenZip("c:/temp/sampleText.zip")
If (success = False) Then
    Debug.WriteLine(zip2.LastErrorText)
    Exit Sub
End If


' Get the text file entry.
Dim entry As New Chilkat.ZipEntry

success = zip2.EntryOf("hello.txt",entry)

If (success = False) Then
    Debug.WriteLine("Entry not found.")
    Exit Sub
End If


' Get the compressed ZIP entry data as Base64.
' 
' This is the compressed data stored inside the ZIP file,
' not the uncompressed text "Hello from a ZIP entry!".
Dim b64 As String = entry.CopyToBase64()

Debug.WriteLine("Base64 compressed ZIP entry data:")
Debug.WriteLine(b64)

zip2.CloseZip()

Debug.WriteLine("Done.")