透视可观察的集合 [英] Pivot an observable collection

问题描述

我在可观察的收藏集中有这样的记录

I have records like this in observable collection

ID Department salary joingdate 
1    .NET   5000  04/08/2011
2    .NET   6000  04/07/2011
3    JAVA   7000  04/08/2011
4    JAVA   8000  04/07/2011
5    .NET   9000  04/06/2011

现在我想要新的可观察的集合，例如

now I want new observable collection like

Joingdate    .NET(Salary)  JAVA(Salary)
04/08/2011  5000        7000
04/07/2011  6000        8000
04/06/2011  9000        NULL

我将如何获得这种可观察的集合?

How would I get this type of observable collection?

推荐答案

假定您具有与您的结构相似的以下结构:

Assuming you have follwing structure that resembles your structure:

public class Data1
{
    public int Id { get; set; }
    public String Dep { get; set; }
    public int Sal { get; set; }
    public String JoinDate { get; set; }
}

public class Data2
{
    public Data2()
    {
        Sal = new List<int>();
    }

    public List<int> Sal { get; set; }
    public String JoinDate { get; set; }

    public override string ToString()
    {
        return Sal.Aggregate(JoinDate, (current, s) => current + s.ToString());
    }
}

以及以下可观察的集合:

And following observable collections:

public class Data1List : ObservableCollection<Data1>
{
    public Data1List()
    {
        Add(new Data1{ Id = 1, Dep = ".NET", Sal = 5000, JoinDate = "04/08/2011"});
        Add(new Data1{ Id = 2, Dep = ".NET", Sal = 6000, JoinDate = "04/07/2011"});
        Add(new Data1{ Id = 3, Dep = "JAVA", Sal = 7000, JoinDate = "04/08/2011"});
        Add(new Data1{ Id = 4, Dep = "JAVA", Sal = 8000, JoinDate = "04/07/2011"});
        Add(new Data1{ Id = 5, Dep = ".NET", Sal = 9000, JoinDate = "04/06/2011"});
    }
}

public class Data2List : ObservableCollection<Data2>
{
}

您可以尝试使用以下代码来解决问题，或者至少可以帮助您找到更好的解决方案:

You could try this code to solve your problem or at least get you on the way to a maybe better solution:

var l1 = new Data1List();
var l2 = new Data2List();

foreach (var items in l1.GroupBy(d => d.JoinDate))
{
    var d2 = new Data2 { JoinDate = items.Key };
    foreach (var item in items)
        d2.Sal.Add(item.Sal);
    l2.Add(d2);
}

我希望这可以帮助您找到解决方案！ :)

I hope this helps you getting to a solution! :)

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