C# Linq 将元素从一个列表<custom>添加到另一个列表，比较它们并更改值

Question

i试图实现允许比较2个列表的功能，如果这两个都有相同的值(id(，第二个列表将叠加该元素值在第一个列表中，else else第二列表中的元素将添加

private List<PotionManager.Potion.Eff> effs = new List<PotionManager.Potion.Eff>();
public string id
{
    set
    {
        var _effs = new List<PotionManager.Potion.Eff>(PM.GetEffectsOnPotion(value).Select(x => x.Clone()));
        foreach (PotionManager.Potion.Eff _eff in _effs)
        {
            var eff = effs.Find(x => x.id == _eff.id);
            if (eff != null)
            {
                eff.power = _eff.power;
                eff.time = _eff.time;
            }
            else
            {
                effs.Add(_eff);
            }
        }
    }
}

是否有更有效的方法而不是foreach？

Answer 1

尝试以下：

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
}
public class UserComparer : IEqualityComparer<User>
{
    public bool Equals(User x, User y) => x.Id == y.Id;
    public int GetHashCode(User obj) => base.GetHashCode();
}

在主要方法中：

var list1 = new List<User>
    {
        new User{Id = 1, Name = "Ted" },
        new User{Id = 2, Name = "Jhon" },
        new User{Id = 3, Name = "Alex" }
    };
var list2 = new List<User>
    {
        new User{Id = 2, Name = "Jhon" },
        new User{Id = 3, Name = "Alex" },
        new User{Id = 4, Name = "Sam" },
    };
var result = list1.Union(list2, new UserComparer());

结果将包含4个元素： 1 Ted，2 Jhon，3 Alex，4 Sam

我希望这对您有帮助