这将使用distinct(没有重复元素的元素)并再次将其转换为列表:

List<type> myNoneDuplicateValue = listValueWithDuplicate.Distinct().ToList();

在Java中(我认为c#或多或少是相同的):

list = new ArrayList<T>(new HashSet<T>(list))

如果你真的想改变原来的列表:

List<T> noDupes = new ArrayList<T>(new HashSet<T>(list));
list.clear();
list.addAll(noDupes);

为了保持顺序，只需将HashSet替换为LinkedHashSet。

我喜欢使用这个命令:

List<Store> myStoreList = Service.GetStoreListbyProvince(provinceId)
                                                 .GroupBy(s => s.City)
                                                 .Select(grp => grp.FirstOrDefault())
                                                 .OrderBy(s => s.City)
                                                 .ToList();

我的列表中有这些字段:Id、StoreName、City、PostalCode 我想在一个有重复值的下拉列表中显示城市。 解决方案:按城市分组，然后选择列表中的第一个城市。

你可以使用Union

obj2 = obj1.Union(obj1).ToList();

根据删除重复，我们必须应用下面的逻辑，所以它将以快速的方式删除重复。

public class Program
{

    public static void Main(string[] arges)
    {
        List<string> cities = new List<string>() { "Chennai", "Kolkata", "Mumbai", "Mumbai","Chennai", "Delhi", "Delhi", "Delhi", "Chennai", "Kolkata", "Mumbai", "Chennai" };
        cities = RemoveDuplicate(cities);

        foreach (var city in cities)
        {
            Console.WriteLine(city);
        }
    }

    public static List<string> RemoveDuplicate(List<string> cities)
    {
        if (cities.Count < 2)
        {
            return cities;
        }

        int size = cities.Count;
        for (int i = 0; i < size; i++)
        {
            for (int j = i+1; j < size; j++)
            {
                if (cities[i] == cities[j])
                {
                    cities.RemoveAt(j);
                    size--;
                    j--;
                }
            }
        }
        return cities;
    }
}

有很多方法可以解决列表中的重复问题，下面是其中之一:

List<Container> containerList = LoadContainer();//Assume it has duplicates
List<Container> filteredList = new  List<Container>();
foreach (var container in containerList)
{ 
  Container duplicateContainer = containerList.Find(delegate(Container checkContainer)
  { return (checkContainer.UniqueId == container.UniqueId); });
   //Assume 'UniqueId' is the property of the Container class on which u r making a search

    if(!containerList.Contains(duplicateContainer) //Add object when not found in the new class object
      {
        filteredList.Add(container);
       }
  }

干杯 拉维Ganesan