Question

List<NeWClient> ListofNewClient = new List < NeWClient >{
                new NeWClient {   ClientID = 1, ClientName = "Nilesh", companyLocation = "Mumbai", companyName = "CG" },
                 new NeWClient {   ClientID = 101, ClientName = "Rahul", companyLocation = "USA", companyName = "TATA" }
               };

        List<OldClient> ListofOldClient = new List<OldClient>{
            new OldClient {   ClientID = 1, ClientName = "Nilesh", companyLocation = "Mumbai", companyName = "CG" },
            new OldClient {   ClientID = 3, ClientName = "Mary", companyLocation = "UK", companyName = "KG" },
            new OldClient {   ClientID = 7, ClientName = "jhon", companyLocation = "USA", companyName = "TG" },
            new OldClient {   ClientID = 9, ClientName = "Tom", companyLocation = "India", companyName = "PG" }
           };

    var  Common = ListofNewClient.Where(n => ListofOldClient.Any(o => o.ClientID == n.ClientID)).ToList();
    var  Deleted = ListofOldClient.Where(o => !ListofNewClient.Any(n => n.ClientID == o.ClientID)).ToList();
    var  NewlyAdded = ListofNewClient.Where(n => !ListofOldClient.Any(o => o.ClientID == n.ClientID)).ToList();

以上对于普通的，已删除的，新添加的都可以正常工作，但是我无法通过与oldClient进行比较来找到更新或修改过的newClinet

        List<NeWClient> ListofNewClient1 = new List<NeWClient>{
            new NeWClient {   ClientID = 200, ClientName = "Dinesh", companyLocation = "Surat", companyName = "nts" },
           };

        List<OldClient> ListofOldClient1 = new List<OldClient>{
            new OldClient {   ClientID = 200, ClientName = "Dinesh", companyLocation = "Mumbai", companyName = "nts" },
            new OldClient {   ClientID = 3, ClientName = "Mary", companyLocation = "UK", companyName = "KG" },
           };

所需结果： 当我们与ListofOldClient1比较时，此处的ListofNewClient1值会更改，因此所需结果将来自ListofNewClient1，如下所示

ClientID = 200，ClientName =“ Dinesh”，companyLocation =“ Surat”，companyName =“ nts”

Answer 1

您可以将Set操作与自定义数据比较器一起使用。

给出这些比较器：

class ClientComparer : IEqualityComparer<NeWClient>
{
    public bool Equals(NeWClient x, NeWClient y)
    {
        return x.ClientID == y.ClientID &&
        x.ClientName == y.ClientName &&
        x.companyLocation == y.companyLocation &&
        x.companyName == y.companyName;
    }

    public int GetHashCode(NeWClient obj)
    {
        unchecked
        {
            if (obj == null)
                return 0;
            int hashCode = obj.ClientID.GetHashCode();
            hashCode = hashCode * 23 + obj.ClientName.GetHashCode();
            hashCode = hashCode * 23 + obj.companyLocation.GetHashCode();
            hashCode = hashCode * 23 + obj.companyName.GetHashCode();
            return hashCode;
        }
    }
}

class NewClientIDComparer : IEqualityComparer<NeWClient>
{
    public bool Equals(NeWClient x, NeWClient y)
    {
        return x.ClientID == y.ClientID;
    }

    public int GetHashCode(NeWClient obj)
    {
        unchecked
        {
            if (obj == null)
                return 0;
            int hashCode = obj.ClientID.GetHashCode();
            return hashCode;
        }
    }
}

您可以通过以下方式获取ClientID通用的修改对象：

//common list
var common = ListofNewClient.Intersect(ListofOldClient, new NewClientIDComparer()).Select(lnc => lnc.ClientID);

var commonOriginal = ListofNewClient.Where(f => common.Contains(f.ClientID));
var commonOld = ListofOldClient.Where(f => common.Contains(f.ClientID));

var updates = commonOld.Except(commonOriginal, new ClientComparer());

如何通过使用linq或Reflection比较2个列表来获取更新或修改后的列表记录

1 个答案: