如何使用linq to xml在两个不同的xml文件中查找匹配的节点

Question

我只是在这里问了另一个问题，答案就在现场。

但这解决了本质上的语法问题。 现在，我需要有关实际解决方案的帮助。

这与之前的问题中的代码相同（已修复并添加了内容）。

XElement FILE1 = XElement.Load (@"..\FILE1.XML");
XElement FILE2 = XElement.Load (@"..\FILE2.XML");

var orders = from file1 in FILE1.Descendants("Players").Elements("Player")
                        select new {
                            name=new {
                                clientID=ulm.Element("ClientID").Value,
                                firstName=file1.Element("FirstName").Value,
                                lastName=file1.Element("LastName").Value
                            }                           
                        };

var orders2 = 
             from file2 in FILE2.Descendants("Players").Elements("Player")
                        select new {
                            name=new {
                                clientID=ulm.Element("ClientID").Value,
                                firstName=file2.Element("FirstName").Value,
                                lastName=file2.Element("LastName").Value
                            }                           
                        };

var matchingResults = from i in orders from j in orders2 where (i.name.firstName==j.name.firstName && i.name.lastName==j.name.lastName)
                            select i;
matchingResults.Dump()     

为了使它有趣，我在尝试将它们匹配之前，已向每个序列结果添加了一个ClientID。

我需要知道的是orders2的玩家节点中的订单EXISTS中的玩家节点。 还是不存在？ 理想情况下，我还可以为NOT EXISTS / EXISTS检查选择选择标准。 （姓氏或名字&&姓氏，或仅ClientID等）

我没有想法如何去做。 谢谢你的帮助。

Answer 1

• 使用Enumerable.Intersect或Enumerable.Except
• 使用具体类型而不是匿名类型。

• 为了能够选择选择标准，您可以创建一个参数化的IEqualityComparer<Client> 。

   class Client { public string ClientID { get; set; } public string FirstName { get; set; } public string LastName { get; set; } } [Flags] enum Criteria { ClientID, FirstName, LastName } class ClientEqualityComparer : IEqualityComparer<Client> { private Criteria criteria; public ClientEqualityComparer(Criteria criteria) { this.criteria = criteria; } #region IEqualityComparer<Client> Membres public bool Equals(Client x, Client y) { if (criteria.HasFlag(Criteria.ClientID) && x.ClientID != y.ClientID) return false; if (criteria.HasFlag(Criteria.FirstName) && x.FirstName != y.FirstName) return false; if (criteria.HasFlag(Criteria.LastName) && x.LastName != y.LastName) return false; return true; } public int GetHashCode(Client obj) { int hash = 17; if (criteria.HasFlag(Criteria.ClientID)) hash = hash * 31 + obj.ClientID; if (criteria.HasFlag(Criteria.FirstName)) hash = hash * 31 + obj.FirstName; if (criteria.HasFlag(Criteria.LastName)) hash = hash * 31 + obj.LastName; } #endregion } static void Main(string[] args) { IEnumerable<Client> orders; IEnumerable<Client> orders2; //... var matchingIdFn = orders.Intersect(orders2, new ClientEqualityComparer(Criteria.ClientID | Criteria.FirstName)); var matchingIdFnLn = orders.Intersect(orders2, new ClientEqualityComparer(Criteria.ClientID | Criteria.FirstName | Criteria.LastName)); var different = orders.Except(orders2, new ClientEqualityComparer(Criteria.ClientID | Criteria.FirstName)); } 

---

var orders = from file1 in FILE1.Descendants("Players").Elements("Player")
                    select new Client{
                        ClientID=ulm.Element("ClientID").Value,
                        FirstName=file1.Element("FirstName").Value,
                        LastName=file1.Element("LastName").Value                        
                    };

Answer 2

我同意艾哈迈德·克莱姆（Ahmed KRAIEM）使用Intersect或Except的建议

这是另一个解决方案，可让您使用任意lambda进行比较：

void Main()
{
XElement FILE1 = XElement.Parse(
@"<Root>
    <Players>
        <Player><ClientId>1</ClientId><FirstName>Bob</FirstName><LastName>Smith</LastName></Player>
        <Player><ClientId>2</ClientId><FirstName>John</FirstName><LastName>Smith</LastName></Player>
    </Players>
</Root>");
    XElement FILE2 = XElement.Parse(
@"<Root>
    <Players>
        <Player><ClientId>2</ClientId><FirstName>Bob</FirstName><LastName>Smith</LastName></Player>
        <Player><ClientId>3</ClientId><FirstName>Mike</FirstName><LastName>Smith</LastName></Player>
    </Players>
</Root>");

var orders = from file1 in FILE1.Descendants("Players").Elements("Player")
                    select new Player(Int32.Parse(file1.Element("ClientId").Value), file1.Element("FirstName").Value, file1.Element("LastName").Value);

var orders2 = from file2 in FILE2.Descendants("Players").Elements("Player")
                    select new Player(Int32.Parse(file2.Element("ClientId").Value), file2.Element("FirstName").Value, file2.Element("LastName").Value);

//orders.Dump();
//orders2.Dump();

var exists = orders2.Intersect(orders, new LambdaEqualityComparer<Player>((i, j) => i.FirstName == j.FirstName && i.LastName == j.LastName));
// or
//var exists = orders2.Intersect(orders, new LambdaEqualityComparer<Player>((i, j) => i.ClientId == j.ClientId));
exists.Dump();

var notExists = orders2.Except(orders, new LambdaEqualityComparer<Player>((i, j) => i.FirstName == j.FirstName && i.LastName == j.LastName));
// or
//var notExists = orders2.Except(orders, new LambdaEqualityComparer<Player>((i, j) => i.ClientId == j.ClientId));
notExists.Dump();
}

public class Player
{
public int ClientId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }

public Player(int clientId, string firstName, string lastName)
{
    ClientId = clientId;
    FirstName = firstName;
    LastName = lastName;
}
}

public class LambdaEqualityComparer<T> : IEqualityComparer<T>
{
private Func<T, T, bool> EqualityComparer { get; set; }

public LambdaEqualityComparer(Func<T, T, bool> equalityComparer)
{
    EqualityComparer = equalityComparer;
}

public bool Equals(T x, T y)
{
    return EqualityComparer(x, y);
}

public int GetHashCode(T obj)
{
    // If the hash codes are different, then Equals never gets called. Make sure Equals is always called by making sure the hash codes are always the same.
    // (Underneath, the .NET code is using a set and the not (!) of a Find method to determine if the set doesn't already contain the item and should be added.
    // Find is not bothering to call Equals unless it finds a hash code that matches.)
    //return obj.GetHashCode();
    return 0;
}
}

请注意，如果您不想创建Player对象，则可以将其完全删除，像以前一样填充orders和orders2匿名对象，并创建一个new LambdaEqualityComparer<dynamic>而不是new LambdaEqualityComparer<Player> ，但由于动态调用会导致速度变慢。