C# EF去除重复列DistinctBy

1.添加一个扩展方法

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public static class DistinctByClass     {         public static IEnumerable<TSource> DistinctBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)         {             HashSet<TKey> seenKeys = new HashSet<TKey>();             foreach (TSource element in source)             {                 if (seenKeys.Add(keySelector(element)))                 {                     yield return element;                 }             }         }     }

2.使用方法如下（针对ID，和Name进行Distinct）

var query = people.DistinctBy(p => new { p.Id, p.Name });

3.若仅仅针对ID进行distinct：

var query = people.DistinctBy(p => p.Id);　　

转 https://www.cnblogs.com/hsjloveit/p/12509818.html