去除重复类型对象BookInfo示例：

bookList = bookList.Distinct(new DataRowComparer()).ToList(); //去除重复书籍/// 
/// 自定义书籍比较(去重)/// 
public class DataRowComparer : IEqualityComparer
     
      {    public bool Equals(BookInfo b1, BookInfo b2)    {        return (b1.BookId == b2.BookId); //去重    }    public int GetHashCode(BookInfo b)    {        return b.ToString().GetHashCode();    }}
     

 

推荐使用这种：

return list.Distinct(o => o.Id).ToList();//去重

public static class EnumerableExtender    {        public static IEnumerable
     
       Distinct
      
       (this IEnumerable
       
         source, Func
        
          keySelector)        {            HashSet
         
           seenKeys = new HashSet
          
           (); foreach (TSource element in source) { var elementValue = keySelector(element); if (seenKeys.Add(elementValue)) { yield return element; } } } }
          
         
        
       
      
     

 

去除单一类型元素：

List
     
       list = new List
      
       ();list.Add("a");list.Add("a");list.Add("b");list.Add("c");list.Add("b");list = list.Distinct().ToList();
      
     

 

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