如何使用EPPlus创建含IRM的Excel文档并限制特定用户访问

Hey there, great question! Let me break this down clearly for you:

First off, EPPlus (whether the older free versions or the paid EPPlus 5+) does not natively support adding Information Rights Management (IRM) protection during document creation. IRM is a Microsoft Office-specific feature tied to their Rights Management Services (RMS), and EPPlus as a third-party library doesn’t integrate with that underlying system.

That said, you have a couple of workarounds to achieve your goal:

• Use Office Interop or PowerShell post-creation
  After generating your Excel file with EPPlus, you can use Office's COM-based Interop libraries or PowerShell to open the file and apply IRM settings. Here's a quick PowerShell example to restrict access to a specific user:

  $excel = New-Object -ComObject Excel.Application
  $excel.Visible = $false
  $workbook = $excel.Workbooks.Open("C:\path\to\your\file.xlsx")
  
  # Enable IRM and set permissions
  $workbook.Permissions.Enabled = $true
  $workbook.Permissions.Add("john.doe@company.com", 1) # 1 = Allow read access
  $workbook.Permissions.AllowPrinting = $false # Optional: restrict printing
  
  $workbook.Save()
  $workbook.Close()
  $excel.Quit()
  

  Note: This requires Office to be installed on the machine running the script, and might not be ideal for server environments where Office isn’t licensed or available.

• Leverage Microsoft Graph API (for cloud-based workflows)
  If you're working with Microsoft 365/Azure, you can upload the EPPlus-generated Excel file to OneDrive or SharePoint, then use the Microsoft Graph API to apply IRM policies. This method doesn’t require local Office installations and works well for cloud-native applications, though it does involve setting up API permissions and making HTTP requests to manage document rights.

As you discovered, embedding a Workbook_Open() VBA macro isn’t a reliable solution—most enterprise environments block macros by default for security reasons, so this approach will fail for many users.

To sum up: EPPlus can’t handle IRM directly, but you can pair it with Office Interop/PowerShell or Microsoft Graph to add the protection after creating the file.

内容的提问来源于stack exchange，提问作者JonO