Dart Requires Chilkat v11.0.0+

Get Compressed ZIP Entry Data as Base64 Using ZipEntry.CopyToBase64

See more Zip Examples

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.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  var success = false;

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

  final zip = CkZip();

  try {
    zip.newZip('c:/temp/sampleText.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Add a small text file from memory.
  // The text is stored in the ZIP as "hello.txt".
  try {
    zip.addString('hello.txt', 'Hello from a ZIP entry!', 'utf-8');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Write the ZIP archive to disk and close it.
  try {
    zip.writeZipAndClose();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

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

  final zip2 = CkZip();

  try {
    zip2.openZip('c:/temp/sampleText.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Get the text file entry.
  final entry = CkZipEntry();

  success = zip2.entryOf('hello.txt', entry);

  if (!success) {
    print('Entry not found.');
    return;
  }

  // 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!".
  final b64 = entry.copyToBase64();

  print('Base64 compressed ZIP entry data:');
  print(b64);

  zip2.closeZip();

  print('Done.');
}