How set defaultDocument by value POST

How set defaultDocument by value POST
Example : Annotation?file=Sample.docx
WebForms C#

@chokpaisan.s

If you are evaluating our GroupDocs.Annotation WebForms application. You could set a default document in configuration.yml file. Please note that GroupDocs.Annotation is a UI-Agnostic, back-end API. You can create and manipulate UI as you want.

Can i dynamic file to GroupDocs.Annotation in javascript?

@chokpaisan.s

Please note that the API is UI-Agnostic. GroupDocs.Annotation for .NET is a back-end API that could be integrated in any .NET project without any third party tool or software dependency.
Have a look at the following code to add arrow annotation:

using (Annotator annotator = new Annotator("input.pdf"))
{
	ArrowAnnotation arrow = new ArrowAnnotation
    {
        Box = new Rectangle(100, 100, 100, 100),
        CreatedOn = DateTime.Now,
        Message = "This is arrow annotation",
        Opacity = 0.7,
        PageNumber = 0,
        PenColor = 65535,
        PenStyle = PenStyle.Dot,
        PenWidth = 3,
        Replies = new List<Reply>
        {
        	new Reply
            {
            	Comment = "First comment",
                RepliedOn = DateTime.Now
            },
            new Reply
            {
             	Comment = "Second comment",
                RepliedOn = DateTime.Now
            }
        }
    };
    annotator.Add(arrow);
    annotator.Save("result.pdf");
}

You can see it is taking a source file as input. Now it’s up to you how do you pass the source file to Annotator class.

Could you please share more details and we’d happily assist you.