(C#) Append Files to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append files 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 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.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

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

// The NewZip method only initializes the Zip object -- it does
// not create or write a .zip file.
bool success = zip.NewZip("notUsed.zip");
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

// Add a reference to a file.  This is the file that will
// be added to a pre-existing .zip archive.  
// Note: this does not read or compress the file contents --
// it simply adds a reference to the zip object.
bool saveExtraPath = false;
success = zip.AppendOneFileOrDir("something.dat",saveExtraPath);
if (success != true) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

// Appends the contents of the 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) {
    Debug.WriteLine(zip.LastErrorText);
    return;
}

Debug.WriteLine("Success!");

// 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