How to check if directory 1 is a subdirectory of dir2 and vice versa

Question

What is an easy way to check if directory 1 is a subdirectory of directory 2 and vice versa?

I checked the Path and DirectoryInfo helperclasses but found no system-r

Answer 1

public static bool IsSubfolder(DirectoryInfo parentPath, DirectoryInfo childPath)
{
return parentPath.FullName.StartsWith(childPath.FullName+Path.DirectorySeparatorChar);
}