Append In-Memory Data to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append in-memory data (string or byte array) to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files or data to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

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Dim zip As New Chilkat.Zip()

Dim success As Boolean

'  Any string unlocks the component for the 1st 30-days.
success = zip.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    MsgBox(zip.LastErrorText)
    Exit Sub
End If


'  The NewZip method only initializes the Zip object -- it does
'  not create or write a .zip file.
success = zip.NewZip("notUsed.zip")
If (success <> true) Then
    MsgBox(zip.LastErrorText)
    Exit Sub
End If



Dim inZipFilename As String
Dim strData As String
Dim strCharset As String
inZipFilename = "something.txt"
strData = "abcdefghijklmnopqrstuvwxyz1234567890"
strCharset = "iso-8859-1"
'  Append a string as a file to the existing zip object.
'  Please read the notes about strCharset below.
zip.AppendString2(inZipFilename,strData,strCharset)

'  Note: The AppendString method is identical to AppendString2,
'  except the strCharset argument is omitted and it is assumed
'  you desire the ANSI charset.

'  Note: You may append a byte array (or Variant containing
'  a byte array for ActiveX users) by calling AppendData.

'  Appends the contents of this zip object to the preExisting.zip
'  zip archive.  preExisting.zip is opened, and the files
'  referenced by this zip object are streamed in, compressed,
'  and appended to the end of the archive.
success = zip.QuickAppend("preExisting.zip")
If (success <> true) Then
    MsgBox(zip.LastErrorText)
    Exit Sub
End If


MsgBox("Success!")

'  Note about strCharset:
'  string variables in many programming language are Unicode.
'  It is likely that you don't want to create .zip that contains
'  a text file that will unzip to Unicode characters (2 bytes/char).
'  The strCharset argument allows you to specify the exact
'  charset to use.  When the string is added to the .zip, it
'  is first converted to this charset.  English strings
'  may use "us-ascii".  Western-European languages typically
'  use "iso-8859-1" or "windows-1252".  Japanese might choose
'  between "shift_jis", "iso-2022-jp", "euc-jp", etc.
'  Chilkat supports all major character encodings.
'  You may always use "ansi" or "utf-8".

'  Note: Additional files, directory trees, or in-memory data
'  can be appended by calling AppendOneFileOrDir, AppendFiles,
'  AppendString, AppendData, etc. multiple times.
'  Whatever files and/or in-memory data that are referenced by
'  this zip object will be appended to preExisting.zip when
'  QuickAppend is called.