How to display "" in a text box in ASP.NET

To complement the (perfectly valid) solution 1, let me explain you what is going on.

Since the strings are delimited by double quotes, if you want a double quote in the string you have two ways to do that:

1- By escaping the double quotes you want to put in the string (like in solution 1); escape character is backslash (\).

2- By doubling each double-quote you want in the string, but then you have to use a string literal. Thus, adapted to your question:

txtabc.Text = @"""""";

Hope this helps.