When you protect your PDF documents with passwords you can optionally specify a set of permissions. The permissions determine how users can interact with the file. For example, you can apply permissions to your document to prohibit the user from printing or using cut and paste operations. This article demonstrates how to change security permissions of PDF documents using Spire.PDF for .NET in C# and VB.NET.
Install Spire.PDF for .NET
To begin with, you need to add the DLL files included in the Spire.PDF for.NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.PDF
Change Security Permissions of a PDF Document
The following are the steps to apply security permissions to a PDF document using Spire.PDF for .NET.
- Create a PdfDocument object.
- Load a sample PDF file using PdfDocument.LoadFileFile() method.
- Specify open password and permission password. The open password can be set to empty so that the generated document will not require a password to open.
- Encrypt the document with the open password and permission password, and set the security permissions using PdfDocument.Security.Encypt() method. This method takes PdfPermissionsFlags enumeration as a parameter, which defines user access permissions for an encrypted document.
- Save the document to another PDF file using PdfDocument.SaveToFile() method.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Security;
namespace ChangeSecurityPermission
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a sample PDF file
doc.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.pdf");
//Specify open password
string openPsd = string.Empty;
//Specify permission password
string permissionPsd = "e-iceblue";
//Encrypt the document with open password and permission password, and set the permissions and encryption key size
doc.Security.Encrypt(openPsd, permissionPsd, PdfPermissionsFlags.FullQualityPrint, PdfEncryptionKeySize.Key128Bit);
//Save the document to another PDF file
doc.SaveToFile("SecurityPermissions.pdf");
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
