Question

让我说我有这样的事情：

public class Subscriber{
    public string Name {get; set;}  
}

public class SomeData{
    public string Content {get; set;}   
}

public class InputData {
    public Subscriber Subscribers { get; set; }
    public IEnumerable<SomeData> DataItems { get; set; }
}

public class QueueItem {
    public IEnumerable<Subscriber> Subscribers { get; set; }
    public IEnumerable<SomeData> DataItems { get; set; }
}

现在让我说我得到一个List<InputData>充满＆＃34;订阅者＆＃34;以及每个订户的数据列表。

现在我要比较每个订阅者的数据列表，最后得到List<QueueItem>，如果2个订阅者拥有相同的数据项集，则它们将为1 QueueItem。< / p>

希望这是有道理的

Answer 1

该技术使用EqualityComparer和Enumerable.SequenceEqual（）

public class Subscriber
{
    public string Name { get; set; }

    // For compare
    public override bool Equals(object obj) { return string.Equals(this.Name, ((Subscriber)obj).Name); }
    public override int GetHashCode() { return this.Name.GetHashCode(); } 
}

public class SomeData
{
    public string Content { get; set; }

    // For compare
    public override bool Equals(object obj) { return string.Equals(this.Content, ((SomeData)obj).Content); }
    public override int GetHashCode() { return this.Content.GetHashCode(); } 
}

public class InputData
{
    public Subscriber Subscribers { get; set; }
    public IEnumerable<SomeData> DataItems { get; set; }

    // Should always initialize an empty collection
    public InputData() { this.DataItems = new List<SomeData>(); }
}

public class QueueItem
{
    public IEnumerable<Subscriber> Subscribers { get; set; }
    public IEnumerable<SomeData> DataItems { get; set; }

    // Should always initialize an empty collection
    public QueueItem() { this.Subscribers = new List<Subscriber>(); this.DataItems = new List<SomeData>(); }
}

public class DataItemsEqualityComparer : EqualityComparer<IEnumerable<SomeData>>
{

    public override bool Equals(IEnumerable<SomeData> x, IEnumerable<SomeData> y)
    {
        return Enumerable.SequenceEqual(x.OrderBy(i => i.Content), y.OrderBy(i => i.Content));
    }

    public override int GetHashCode(IEnumerable<SomeData> obj)
    {
        return obj.Select(i => i.GetHashCode()).Sum().GetHashCode();
    }
}

用法

var data = new List<InputData>();
var fruits = new[] { new SomeData() { Content = "apple" }, new SomeData() { Content = "pear"} };
var colors = new[] { new SomeData() { Content = "red" }, new SomeData() { Content = "blue" }, new SomeData() { Content = "green" } };

data.Add(new InputData() { Subscribers = new Subscriber() { Name = "Alice" }, DataItems = new List<SomeData>(fruits) });
data.Add(new InputData() { Subscribers = new Subscriber() { Name = "Bob" }, DataItems = new List<SomeData>(colors) });
data.Add(new InputData() { Subscribers = new Subscriber() { Name = "Charlie" }, DataItems = new List<SomeData>(fruits) });

List<QueueItem> groupedData = data.GroupBy(
    i => i.DataItems, 
    i => i.Subscribers, 
    new DataItemsEqualityComparer())
    .Select(i => new QueueItem() { Subscribers = i, DataItems = i.Key }).ToList();

结果

QueueItem :
  Subscribers:
  - Alice
  - Charlie
  Data:
  - apple
  - pear
QueueItem :
  Subscribers:
  - Bob
  Data:
  - red
  - blue
  - green

Answer 2

var queue = Dictionary(Subscriber, List<SomeData>);
//And lets just for example add some data
var items1 = new List<SomeData>();
items1.Add(new SomeData("test"));
items1.Add(new SomeData("test2"));

var items2 = new List<SomeData>();
items2.Add(new SomeData("test"));

queue.Add(new Subscriber("Peter"), items1);
queue.Add(new Subscriber("Luke"), items1);
queue.Add(new Subscriber("Anna"), items2);

Dictionary<Subscriber, List<SomeData>> myDictionary = queue
    .GroupBy(o => o.PropertyName)
    .ToDictionary(g => g.Key, g => g.ToList());

按列表内容对项目进行分组

2 个答案: