Example create signature field AcroForm with Blazor Server App

ตัวอย่างการสร้าง Signature Field แบบ AcroForm ในเอกสาร PDF โดยใช้ iTextSharp (LGPL/MPL) v4.1.6 หรือ iTextSharp.LGPLv2.Core v1.7.4
สำหรับการพัฒนาด้วย Visual Studio Community 2019 v16.10.3 / C# / Microsoft Framework .NET 5 / Project แบบ Blazor Server App หรือ ASP.NET Core Web App
Source Reference:

• https://github.com/topics/itextsharp
  
• https://github.com/tossnet/Blazor-PDF

iTextSharp (LGPL / MPL) 4.1.6
iTextSharp is a port of the iText open source Java library for PDF generation written entirely in C# for the .NET platform. This repository contains the source code of the last version of the library released under the Mozilla Public License and the LGPL, before the project moved to the AGPL. You can use this version if you need a free PDF library for use in closed-source projects.
Link https://github.com/schourode/iTextSharp-LGPL

iTextSharp.LGPLv2.Core 1.7.4
Is an port of the last LGPL version of the iTextSharp (V4.1.6) to .NET Core.
Link https://github.com/VahidN/iTextSharp.LGPLv2.Core