元组（或数组）作为C＃中的字典键

如果您使用的是.NET 4.0，请使用元组：

lookup = new Dictionary<Tuple<TypeA, TypeB, TypeC>, string>();

如果不是，则可以定义一个元组并将其用作键。元组需要重写GetHashCode，Equals和IEquatable：

struct Tuple<T, U, W> : IEquatable<Tuple<T,U,W>>{    readonly T first;    readonly U second;    readonly W third;    public Tuple(T first, U second, W third)    {        this.first = first;        this.second = second;        this.third = third;    }    public T First { get { return first; } }    public U Second { get { return second; } }    public W Third { get { return third; } }    public override int GetHashCode()    {        return first.GetHashCode() ^ second.GetHashCode() ^ third.GetHashCode();    }    public override bool Equals(object obj)    {        if (obj == null || GetType() != obj.GetType())        { return false;        }        return Equals((Tuple<T, U, W>)obj);    }    public bool Equals(Tuple<T, U, W> other)    {        return other.first.Equals(first) && other.second.Equals(second) && other.third.Equals(third);    }}