iText Core/Community (previously known as iTextSharp) is a high-performance, battle-tested library that allows you to create, adapt, inspect, and maintain PDF documents, allowing you to add PDF functionality to your software projects with ease. It is also available for Java. For more advanced examples, refer to our Knowledge Base or the main Examples repo. You can find C# equivalents to the Java Signing examples here, though the Java code is very similar since they have the same API. Some...