'Declaration
 
Public Sub Protect( _
   Optional ByVal protection As WorkbookProtection, _
   Optional ByVal password As String _
) 

'Usage
 
Dim instance As Workbook
Dim protection As WorkbookProtection
Dim password As String
 
instance.Protect(protection, password)

public void Protect( 
   WorkbookProtection protection,
   string password
)

Parameters

protection

The WorkbookProtection object that lets you select which actions can be carried out on a protected Workbook.

password

The password that will be used to protect this Workbook. 

Note that the same password must be used to Unprotect the Workbook. However, you can protect a Workbook without using a password. The default setting is, in fact, null, which sets no password for the Protection.

Target Platforms: Windows 11, Windows 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Workbook Class
Workbook Members