Dart Requires Chilkat v11.0.0+

Remove an Entry from an Existing ZIP Using DeleteEntry

See more Zip Examples

This example demonstrates how to use the DeleteEntry method to remove a file from an existing ZIP archive.

The example:

• Creates a ZIP archive containing three text files
• Opens the ZIP archive for modification
• Finds and deletes one entry
• Writes the modified ZIP archive to a new filename

Suppose the original ZIP archive contains:

a.txt
b.txt
c.txt

After deleting b.txt, the modified ZIP archive contains:

a.txt
c.txt

The entry is removed only from the in-memory ZIP object until a Write* method is called.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  var success = false;

  // ------------------------------------------------------------
  // First create a ZIP archive containing three text files.

  final zip = CkZip();

  try {
    zip.newZip('original.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final charset = 'utf-8';

  try {
    zip.addString('a.txt', 'Contents of file A', charset);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    zip.addString('b.txt', 'Contents of file B', charset);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    zip.addString('c.txt', 'Contents of file C', charset);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Write the ZIP archive to disk.
  // 
  // The ZIP now contains:
  // 
  //     a.txt
  //     b.txt
  //     c.txt
  // 
  try {
    zip.writeZipAndClose();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // ------------------------------------------------------------
  // Open the existing ZIP archive for modification.

  final zip2 = CkZip();

  try {
    zip2.openZip('original.zip');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Find the entry named "b.txt".
  final entry = CkZipEntry();

  success = zip2.entryOf('b.txt', entry);
  if (!success) {
    print(zip2.lastErrorText);
    return;
  }

  // Remove the entry from the in-memory ZIP object.
  // 
  // At this point, the original ZIP file on disk is unchanged.
  // The deletion takes effect only after WriteZip or
  // WriteZipAndClose is called.
  try {
    zip2.deleteEntry(entry);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Write the modified ZIP archive to a new file.
  zip2.fileName = 'modified.zip';

  try {
    zip2.writeZipAndClose();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The modified ZIP now contains:
  // 
  //     a.txt
  //     c.txt
  // 

  print('ZIP archive updated successfully.');
}