C list set object de duplication LINQ de duplication with time de duplication

demand ： Only one piece of data can appear at the same time

In actual projects, many implement this interface through specific implementation classes , By rewriting Equals and HashCode Compare attribute values to achieve the goal of de duplication , Because for each class, the corresponding comparator must be implemented , So it's not universal , On the contrary, the best way is to use the above methods , In fact, we can use this comparison interface to achieve a general solution , The reason why we have to implement a comparator for every class is , We put attribute comparison inside the interface of the class , What if we put attribute comparison on the periphery , At this time, the general solution is reached , So how do we achieve it , Through delegation , The essence of implementing this interface is nothing more than comparison HashCode, And then through Equals Compare the values , When comparing HashCode when , We force its value to be a constant （ such as 0）, When rewriting Equals Method we call the delegate , as follows

 1. Create a new class , Yes IEnumerable Expand

public static class Extensions
    {
        public static IEnumerable<T> Distinct<T>(
            this IEnumerable<T> source, Func<T, T, bool> comparer)
            where T : class
            => source.Distinct(new DynamicEqualityComparer<T>(comparer));

        private sealed class DynamicEqualityComparer<T> : IEqualityComparer<T>
            where T : class
        {
            private readonly Func<T, T, bool> _func;

            public DynamicEqualityComparer(Func<T, T, bool> func)
            {
                _func = func;
            }

            public bool Equals(T x, T y) => _func(x, y);

            public int GetHashCode(T obj) => 0;
        }
    }

2. call     Take the time as hours, minutes and seconds to remove the duplicate And sort

var item1 = item.Distinct((a, b) => a.Item3.ToString("T") == b.Item3.ToString("T")).ToList().OrderBy(i=>i.Item3);

After processing