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 class will set this to false.

If true, the class will allow encrypted files to be streamed out during compression; i.e., the class will allow you to compress with WriteToProgressEvent set to true 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 class 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 class 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 True, the class will recalculate the CRC whenever data from the file is added to the archive. In situations where file content may be changing during compression this will ensure a correct CRC.

Use this setting with caution as it can impact performance. The default value is False.

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 class uses the Deflate compression method (a value of 0). Supported values are:

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

If there are no events to process when DoEvents is called, the class will wait for the amount of time specified here before returning. The default value is 20.

The default code page is the Active Code Page (0).

The following is a list of valid code page identifiers:

The following is a list of valid code page identifiers for Mac OS only: