如果Request.QueryString不存在，则设置ASP.NET变量

Question

I want to set a textbox.text to a certain value if Request.QueryString['EQCN'] does not exist. If it does exist, I would like to set it to the value of Requestion.QueryString['EQCN'].

It seems that if the value doesn't exist it defaults the value to be "".

Any ideas?

Thanks so much!!!

Answer 1

If the parameter is not in the query string, the QueryString indexer will return a null reference, so you can use the ?? operator for a default value:

textbox.text = Request.QueryString['EQCN'] ?? "default text";

Answer 2

textbox.text = string.IsNullOrEmpty(Request.QueryString["EQCN"]) ? "my value" : Request.QueryString["EQCN"];