DocX – Password protect Microsoft Word document programmatically

Following code provides basic example usage

static void HelloWorldProtectedDocument()
{
    Console.WriteLine("\tHelloWorldPasswordProtected()");

    // Create a new document.
    using (DocX document = DocX.Create(@"docs\HelloWorldPasswordProtected.docx"))
    {
        // Insert a Paragraph into this document.
        Paragraph p = document.InsertParagraph();

        // Append some text and add formatting.
        p.Append("Hello World!^011Hello World!")
        .Font(new FontFamily("Times New Roman"))
        .FontSize(32)
        .Color(Color.Blue)
        .Bold();

        // Save this document to disk with different options
        // Protected with password for Read Only
        EditRestrictions erReadOnly = EditRestrictions.readOnly;
        document.AddProtection(erReadOnly, "SomePassword");
        document.SaveAs(@"docs\\HelloWorldPasswordProtectedReadOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldPasswordProtectedReadOnly.docx\n");

        // Protected with password for Comments
        EditRestrictions erComments = EditRestrictions.comments;
        document.AddProtection(erComments, "SomePassword");
        document.SaveAs(@"docs\\HelloWorldPasswordProtectedCommentsOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldPasswordProtectedCommentsOnly.docx\n");

        // Protected with password for Forms
        EditRestrictions erForms = EditRestrictions.forms;
        document.AddProtection(erForms, "SomePassword");
        document.SaveAs(@"docs\\HelloWorldPasswordProtectedFormsOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldPasswordProtectedFormsOnly.docx\n");

        // Protected with password for Tracked Changes
        EditRestrictions erTrackedChanges = EditRestrictions.trackedChanges;
        document.AddProtection(erTrackedChanges, "SomePassword");
        document.SaveAs(@"docs\\HelloWorldPasswordProtectedTrackedChangesOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldPasswordProtectedTrackedChangesOnly.docx\n");

        // But it's also possible to add restrictions without protecting it with password.

        // Protected with password for Read Only
        document.AddProtection(erReadOnly);
        document.SaveAs(@"docs\\HelloWorldWithoutPasswordReadOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldWithoutPasswordReadOnly.docx\n");

        // Protected with password for Comments
        document.AddProtection(erComments);
        document.SaveAs(@"docs\\HelloWorldWithoutPasswordCommentsOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldWithoutPasswordCommentsOnly.docx\n");

        // Protected with password for Forms
        document.AddProtection(erForms);
        document.SaveAs(@"docs\\HelloWorldWithoutPasswordFormsOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldWithoutPasswordFormsOnly.docx\n");

        // Protected with password for Tracked Changes
        document.AddProtection(erTrackedChanges);
        document.SaveAs(@"docs\\HelloWorldWithoutPasswordTrackedChangesOnly.docx");
        Console.WriteLine("\tCreated: docs\\HelloWorldWithoutPasswordTrackedChangesOnly.docx\n");

    }
}