Creating a spanned zip file

One extra thing to do

Except for the basic things you have to do to zip or unzip a file, the only extra thing you have to do to create or be able to unzip a spanned zip file is to write a handler for the InsertDisk event. The InsertDisk event is triggered by the library when a new disk must be inserted into the removable media drive in order to continue reading or writing a zip file. The Xceed Zip Compression Library never displays anything on the screen itself (a library should never take that initiative) so you have to display the message box yourself. The advantage is that you get to display whatever you want, any way you want it.

Here is sample VB code you can put in the InsertDisk event's handler for displaying a simple message box to insert a new or specific disk:

Visual Basic	Copy Code
`If nDiskNumber = xcdLastDisk then MessageBox "Please insert the last disk of the zip file set." Else MessageBox "Please insert disk " + Str(nDiskNumber) + " of the zip file set." EndIf`

Here is sample Delphi code you can put in the InsertDisk event's handler for displaying a simple message box to insert a new or specific disk:

Delphi	Copy Code
`if ( lDiskNumber = 0 ) then ShowMessage( 'Please insert the last disk of the zip file set.') else ShowMessage( 'Please insert disk #' + IntToStr( lDiskNumber ) ); bDiskInserted := true;`

When this is done, the library will automatically span disks when you are writing to floppy disks and they get full, or will automatically request the appropriate disks when you are unzipping from a zip file that spans multiple disks.

Xceed Zip Compression Library can also read and write zip files that are split onto multiple files in the same location (as opposed to a zip file split onto multiple disks). See the SplitSize property for information on how to do this.