How can I change an existing link annotation to have Invisible Rectangle?

[Support]

Q: How can I change an existing annotation to have a Link Type of
Invisible Rectangle? I tried it all and I cannot seem to work around
this issue, any help is much appreciated.

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A: You probably want to set the border width in annotation's border
style dictionary to zero. For example:

Annot.BorderStyle bs = annot.GetBorderStyle(); bs.width = 0;
annot.SetBorderStyle(bs);

or

annot.SetBorderStyle(new Annot.BorderStyle
(Annot.BorderStyle.Style.e_solid, 0, 0, 0));