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

bool success;

//  Any string unlocks the component for the 1st 30-days.
success = zip.UnlockComponent("Anything for 30-day trial");
if (success != true) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

//  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) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

string inZipFilename;
string strData;
string strCharset;
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) {
    MessageBox.Show(zip.LastErrorText);
    return;
}

MessageBox.Show("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.