如何使用c＃中的lambda表达式检测元素是否存在？

I've been using a try/catch statement to run through whether or not an element exists when I parse through it. Obviously this isn't the best way of doing it. I've been using LINQ (lambda expressions) for the majority of my parsing, but I just don't know how to detect if an element is there or not.I've been using a try/catch statement to run th