Reading a string line per line in C#

Possible Duplicate:
Easiest way to split a string on newlines in .net?

I'm trying to read out and interpret a string line per line. I took a look at the StringReader class, but I need to find out when I'm on the last line. Here's some pseudocode of what I'm trying to accomplish:

while (!stringReaderObject.atEndOfStream()) {
    interpret(stringReaderObject.readLine());
}

Does somebody know how to do this?

Thanks!

Yvan