Zip Configuration

This setting controls the algorithm that generates AES cryptographic keys from the Password specified. For added security, a random salt value is generated, and a unique key will be generated for every unique combination of Password and salt.

If true, a unique salt value and key will be generated for each file encrypted. If false, a single salt value and key will be generated for all encrypted files in the archive.

If you are encrypting a lot of files, the value of this setting can have a substantial effect on both security and performance. By default, the component will set this to false.

This setting determines whether the archive is closed after calling Compress. When set to False the archive remains open and additional files can be added at any time. This allows files to be added to the archive incrementally as they become available. For instance:

zip.Config("CloseArchiveAfterCompress=false");

//Add one file
zip.Files.Add(new ZIPFile("..\\..\\files\\test.txt"));
zip.Compress();

//Add another file
zip.Files.Clear();
zip.Files.Add(new ZIPFile("..\\..\\files\\test2.txt"));
zip.Compress();

//Ready to finish creating the archive
zip.Config("CloseArchiveAfterCompress=true");

zip.Files.Clear();
zip.Compress(); //Must be called to finish archive creation

The default value of this setting is True.

If true, the component will allow encrypted files to be streamed out during compression; i.e., the component will allow you to compress with WriteToProgressEvent set to true or with SetArchiveOutputStream set to a valid stream and a Password has been set.

Use extreme caution when setting this option, as streamed and encrypted zip files may be unreadable by other zip software.

If set, the component will generate a hash for each file when the file is compressed. After compression, the hash is avaiable through the Files[i].FileHash configuration setting.

The supported algorithms are: "sha1", "sha224", "sha256", "sha384" and "md5".

If FileHashAlgorithm is set, this setting is used to access the hash generated for each file. This setting is read-only.

Setting this value to true will force the component to always create a Zip64 format archive when compressing. By default, this value is false and the component will detect whether or not compressing in Zip64 format is necessary.

If true, the component will mark files as text within the zip archive. This may allow decompression software on other platforms to translate between character sets, etc.

If false (the default), files will be written as binary. To mark some files as text and others as binary, it is recommended that you trap the BeginFile event and set this property value as appropriate for each file.

Specifies whether or not the modified time of the extracted files use the current time or the original time of the file in the archive.

When set to True (default) the extracted files will have the same modified time as the original file.

When set to False the modified time on the extracted files will be set to the current time.

If WriteToProgressEvent is set to true, then all data produced through invocations of Extract, ExtractAll, and Compress will be written to the Progress event as well as to disk. Applications may stream out the compressed or decompressed data by trapping this event and copying the data.

If WriteToProgressEvent is set to false, the data will not be streamed out, and the Data parameter of the Progress event will contain null.

Note that if streaming is enabled the zip files written will be slightly larger. Moreover, zip files produced with WriteToProgressEvent may be incompatible with certain older zip utilities.

By default, Password encryption is not allowed for archives created with WriteToProgressEvent set to true. You may set the EnableStreamingEncryption setting to allow this, but streamed and encrypted zip files may be incompatible with other utilities.

By default, this config is set to false.

This is used to specify different compression methods. By default the component uses the Deflate compression method (a value of 0). Supported values are:

This property is true by default. Therefore, by default, the output stream will be closed after compression is completed. In order to keep streams open after the compression completes, you must set this config to false.

The encoding to be used for filenames, and for Zip files, the password. The file contents are treated as binary data, and so encoding does not apply to the contents. At present only supported for Zip and Jar.

Default - Zip: "" (use default encoding of current machine, if possible)

Default - Jar: "UTF-8"

Example - This would set encoding to Japanese Shift-JIS.

Zip1.Config("Encoding=SJIS");

Files with attributes matching those specified will be excluded from compression or decompression. May be set to any combination of H (hidden), S (system), A (archive), and R (read-only). (Example: "HSR") Alternatively, may be set to a bitmask of the following flags: Readonly (1), Hidden (2), System (4), Directory (16), Archive (32).

For Java, when compressing, attributes other than "H" and "R" will be ignored (due to JRE limitations).

Default: "" (no excluded attributes)

If true, only the files contained within the ArchiveFile are extracted directly to the specified ExtractToPath. Folders contained within the ArchiveFile will not be created within the ExtractToPath. If an archive contains files with the same name, you can control whether or not they get overwritten by setting OverwriteFiles.

If true, the component will overwrite readonly files when decompressing. If false (the default), the component will fire the Error event, instead, and will fail with an exception if the error is not trapped and explicitly ignored in the event.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GuiAvailable to false will ensure that the component does not attempt to process external events.

If set to True, when the component creates a thread the thread's IsBackground property will be explicitly set to True. By default this setting is False.

By default the component will use the system security libraries to perform cryptographic functions. This means calls to unmanaged code will be made. In certain environments this is not desirable. To use a completely managed security implementation set this setting to True. Setting this to True tells the component to use the internal managed implementation instead of using the system's security API.

Note that when this value is set the product's system dll is no longer required as a reference, as all unmanaged code is stored in this file.