inherit from two classes in C# [duplicate]

Multitiple inheritance is not possible in C#, however it can be simulated using interfaces, see Simulated Multiple Inheritance Pattern for C#.

The basic idea is to define an interface for the members on class B that you wish to access (call it IB), and then have C inherit from A and implement IB by internally storing an instance of B, for example:

class C : A, IB
{
    private B _b = new B();

    // IB members
    public void SomeMethod()
    {
        _b.SomeMethod();
    }
}

There are also a couple of other alternaitve patterns explained on that page.