带有Sum()的C#LINQ Lambda多组IEnumerable

本文关键字：Lambda 多组 IEnumerable C#LINQ Sum 带有 | 更新日期: 2025-05-08 12:19:18

我有一个data = IEnumerable<AnalyticsData>的集合，我正试图通过整数列上的多个属性和Sum()进行分组。最终结果将是AnalyticsReportRow<dynamic>()的集合，正如您在下面看到的，尽管这并不是高度相关的。

在最后的Select()方法中，我希望传入一个对象，最好是从原始集合传入，如果可能的话，我不希望在我的链式查询中间重新创建一个对象。大多数示例似乎都创建了一个新的强类型或动态对象，以传递到链中的下一个链接。

以下是我花了几个小时试图处理的内容，这将返回下面第一个代码块中的所有行的集合（我导出为CSV，因此格式化）：

var pageViewsData = analyticsData.GroupBy(data => new { g1 = data.Webproperty, pv = data.PageViews, d = data })
    .GroupBy(data => new { gg1 = data.Key.g1, dd = data.Key.d })
    .Select(data => new AnalyticsReportRow<dynamic>(data.Key.dd, "Page_Views", data.Sum(datas => datas.Key.pv)));

结果是：

"CustomerA","","","","","Page_Views",0,"A1-810","","",2,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"A1-810","","",2,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-N8013","","",2,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",7,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",2,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",3,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",3,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",2,"4/10/2015 16:08:33"

并且希望在倒数第二列显示Sum()，按客户分组，然后按设备分组。例如：

"CustomerA","","","","","Page_Views",0,"A1-810","","",4,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-N8013","","",2,"4/10/2015 16:08:33"
"CustomerA","","","","","Page_Views",0,"GT-P3113","","",16,"4/10/2015 16:08:33"

我很难理解逻辑，我真的可以用一个例子来说明如何像这样分组，甚至是伪代码和动态类型。

谢谢。

带有Sum()的C#LINQ Lambda多组IEnumerable

今天花了几个小时讨论这个问题并发布了我的问题后，我决定尝试更多的东西，并阅读更多关于GroupBy()的文档。

事实证明，我忽略了这样一个事实，即您可以为GroupBy方法提供一个键选择器和一个元素选择器，如MSDN文档中所述。如果我理解正确的话，这提供了一个不同的限定符的能力，该限定符告诉查询如何分组。

最后，这似乎给了我所需要的。我真的很想得到一些反馈，以确保我做得正确：

var pageViewsData = analyticsData.Where(data => data.PageViews > 0)
  .GroupBy(data => new { g1 = data.Webproperty, g2 = data.DeviceModel }, data => data)
  .Select(data => new AnalyticsReportRow<dynamic>(data.FirstOrDefault(), "Page_Views", data.Sum(d => d.PageViews)));

试试这样的东西：

var query = from d in analyticsData
            group d by new { d.Webproperty, d.DeviceModel }
            into g
            select new 
            {
                g.Webproperty,
                g.DeviceModel,
                Total = g.Sum(it => it.PageViews)
            };
var result = query.ToList();
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