Adds a file to an existing archive.
Append may be used to add a file to an existing archive. Unlike IncludeFiles, Append compresses and adds the file to the archive as soon as it is invoked.
DecompressedName should be set to the name of the single file to be added. It should be specified with a path if necessary, to allow the component to find it. The value of CompressedName is the name that will be stored in the archive.
When Append is invoked, the Scan method will first be invoked, if it has not been invoked already. Note that if IncludeFiles has been invoked, or if the values of CompressedName and DecompressedName have been set for that file in the Files collection, this information will be reset by the call to Scan.
After the file is added, the array properties will be updated appropriately.
Due to the nature of the gzip format, Append and Delete are not supported for .tar.gz files.
.NET Standard Notes
To call this method in an asynchronous manner call AppendAsync instead. When the method completes (or an error is encountered) the AppendCompleted event will fire.