First of all, there is a question title that almost exactly matches my question ([strstr() equivalent in C#](https://stackoverflow.com/questions/3536958/strstr-equivalent-in-c-sharp)), but he's referring to a method to do a byte[] comparison version.

I'm looking for a string comparison that outputs the index of the first occurance of str2 in str1, and just cannot find it!

```
string s1 = ("BetYouCantFooFind");
string s2 = ("Foo");

int idx = strstrC#(s1,s2);

```

Surely there is an equivalent?