Check that integer type belongs to enum member

Question

I want to check that some integer type belongs to (an) enumeration member.

For Example,

public enum Enum1
{
    member1 = 4,

    member2 = 5,

    m         


        

Answer 1

int testNum = 5;
bool isMember = Enum.GetValues(typeof(Enum1)).Cast().Any(x => x == testNum);