Protect a Workbook with a Password Using the Syncfusion .NET Excel Library

Overview

The Syncfusion^® .NET Excel Library (XlsIO) enables you to create, read, and edit Excel documents programmatically without Microsoft Excel or interop dependencies. Using this library, you can protect a workbook with a password using C#. After adding workbook protection, structural changes to the workbook are disabled.

Watch this video to see how to protect an Excel workbook with a password using the Syncfusion .NET Excel Library:

Watch the video

Protect a workbook with a password

Follow these steps to protect an Excel workbook with a password using the Syncfusion> .NET Excel Library.

Step 1: Create a new project

Start by creating a new C# Console Application project.

Step 2: Install the NuGet package

Add the Syncfusion.XlsIO.Net.Core package to your project from NuGet.org.

Step 3: Include namespaces

Add the following namespaces to your Program.cs file:

c#
using System;
using System.IO;
using Syncfusion.XlsIO;

Step 4: Add code to protect a workbook with a password

Use the following code in Program.cs to protect an Excel workbook with a password.

Run

c#
using (ExcelEngine excelEngine = new ExcelEngine())
{
    IApplication application = excelEngine.Excel;
    application.DefaultVersion = ExcelVersion.Xlsx;
    FileStream inputStream = new FileStream(Path.GetFullPath(@"Data/InputWorkbook.xlsx"), FileMode.Open, FileAccess.ReadWrite);

    //Open Excel file.
    IWorkbook workbook = application.Workbooks.Open(inputStream);
    IWorksheet worksheet = workbook.Worksheets[0];

    //Protect workbook with password.
    workbook.Protect(true, true, "syncfusion");
    
    #region Save
    //Saving the workbook.
    FileStream outputStream = new FileStream(Path.GetFullPath(@"Output/ProtectedWorkbook.xlsx"), FileMode.Create, FileAccess.Write);
    workbook.SaveAs(outputStream);
    #endregion

    //Dispose streams.
    outputStream.Dispose();
    inputStream.Dispose();
}