Question

我有List对象填充了自定义结构的实例。

        list.Add(new Mail("mail1", "test11", "path11"));
        list.Add(new Mail("mail2", "test12", "path12"));
        list.Add(new Mail("mail1", "test13", "path13"));
        list.Add(new Mail("mail1", "test14", "path14"));
        list.Add(new Mail("mail2", "test15", "path15"));

        var q = from x in list
                group x by x.Sender into g
                let count = g.Count()
                where count > 2
                orderby count descending
                select new { Sender = g.Key};

        foreach (var x in q)
        {
            Console.WriteLine(x.Sender);
        }

该代码的输出将是：

MAIL1

但是因为我需要处理每个基于某个属性（即Sender）的值可用两次以上（或者n次）的邮件项目，我需要一个查询来显示所有发生的项目通常比n（包括对相应邮件项目的引用。

在填写查询后，我很乐意做这样的事情：

    foreach (var x in q)
    {
        Console.WriteLine(x.Sender + " - " + x.Path + " - " + x.Count);
    }

我是LINQ的新手，但我确信这在某种程度上是可能的。

感谢您的帮助

此致凯文

Answer 1

包含要添加到匿名类型的属性。

var q = from x in list
        group x by x.Sender into g
        let count = g.Count()
        where count > 2
        orderby count descending
        select new
        {   // add your fields here
            Sender = g.Key,
            Path = ...,      // not sure what you wanted here
            Count = count,
            Mails = g,       // include the mails in the group
        };

然后你可以用它做你想做的事。

foreach (var x in q)
{
    // each x is a type with the fields
    //     Sender
    //     Path
    //     Count
    //     Mails
    Console.WriteLine(x.Sender + " - " + x.Path + " - " + x.Count);
    foreach (var mail in x.Mails)
    {
        // do something with each individual mail
    }
}

列出List对象中的所有重复项，包括数量

1 个答案: