Generic IEqualityComparer and GetHashCode

Question

Being somewhat lazy about implementing lots of IEqualityComparers, and given that I couldn\'t easily edit class implementations of object being compared, I went with the fol

Answer 1

Try this code:

public class GenericCompare : IEqualityComparer where T : class
{
    private Func _expr { get; set; }
    public GenericCompare(Func expr)
    {
        this._expr = expr;
    }
    public bool Equals(T x, T y)
    {
        var first = _expr.Invoke(x);
        var sec = _expr.Invoke(y);
        if (first != null && first.Equals(sec))
            return true;
        else
            return false;
    }
    public int GetHashCode(T obj)
    {
        return obj.GetHashCode();
    }
}

Example: collection = collection.Except(ExistedDataEles, new GenericCompare(x=>x.Id)).ToList();