How to tell if one string is contained in another string?

cq_blue

str1 = "ddd"
str2 = "dddccc"
str1 is included in str2, how to write it with code? THKS

xinyu5460

string str1 = "ddd";
string str2 = "dddccc";

if (str2.IndexOf (str1)> -1)
{
Console.WriteLine ("contains");
}