转载自诗人江湖老，原文地址

class FuncEqualityComparer<T> : IEqualityComparer<T>
{readonly Func<T, T, bool> _comparer;readonly Func<T, int> _hash;public FuncEqualityComparer( Func<T, T, bool> comparer ): this( comparer, t => 0 ) // NB Cannot assume anything about how e.g., t.GetHashCode() interacts with the comparer's behavior{}public FuncEqualityComparer( Func<T, T, bool> comparer, Func<T, int> hash ){_comparer = comparer;_hash = hash;}public bool Equals( T x, T y ){return _comparer( x, y );}public int GetHashCode( T obj ){return _hash( obj );}
}