Add text annotation to PDF in C# and VB.Net

Please share your working code and also explain in detail what annotation you want to implement.

Hello Arjunv,

i show a pdf preview in a popup. When the popup is loaded i use this method to show the pdf. 

protected void Page_Load(object sender, EventArgs e)
{
    int id = (int)Session["idPopup"];
    string embed = "<object data=\"{0}{1}\" type=\"application/pdf\" width=\"1040px\" height=\"1450px\">";
    embed += "If you are unable to view file, you can download from <a href = \"{0}{1}&download=1\">here</a>";
    embed += " or download <a target = \"_blank\" href = \"http://get.adobe.com/reader/\">Adobe PDF Reader</a> to view the file.";
    embed += "</object>";
    ltEmbed.Text = string.Format(embed, ResolveUrl("~/PreviewPDF.ashx?Id="), id);
}

 All work correctly!!! Now i need to write inside this pdf, or insert some annotations and then save them in a db. I can't enable annotations. How can I add them? Do you have any ideas? Thanks

Please refer below link.

https://www.grapecity.com/blogs/edit-and-review-pdf-documents-with-annotaions-on-the-web

Thank you Arjunv, is there a free tool? 

Thanks

Please refer below link.

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/Annotation/How-to-add-free-text-annotation-to-PDF-in-C-VB.NET.html