How to: Protect a Worksheet

You can protect a worksheet to lock the cells so that end-users can only perform a specific (restricted) set of actions specified by the WorksheetProtectionPermissions enumeration member. To accomplish this, use the Worksheet.Protect method as illustrated in the following code snippet:

Dim worksheet As Worksheet = workbook.Worksheets(0)

' Prevent users from making changes to worksheet elements
If Not worksheet.IsProtected Then
    worksheet.Protect("password", WorksheetProtectionPermissions.Default)
End If
workbook.BeginUpdate()
worksheet("C3:F8").Borders.SetOutsideBorders(Color.Red, BorderLineStyle.Thin)
worksheet("D5:E6").Merge()
worksheet("D5").Value = "Try to change me!"
worksheet("D5").Alignment.Vertical = SpreadsheetVerticalAlignment.Center
workbook.EndUpdate()

To remove protection, the end-user can invoke the Protect Sheet Dialog. In code, use the Worksheet.Unprotect method.