c# - 如何在 LINQ 中插入占位符以便我的组恰好有 24 个点

Question

我正在将一天的 24 小时绘制成图表，但某些时间(例如早上)没有任何意义。当那个小时没有值时，如何更改 linq 以插入“Times = 1”？

所以而不是

4、6、8、5、7、9...

应该是

1, 1, 1, 1, 4, 1, 6, 8, 5, 7, 9...(总是 24 分)

 Lead[] newLeads;

    newLeads = gameManager.leads.Lead;

    string[] logNumbers = (from nl in newLeads
                           //where DateTime.Parse(nl.CreateDate).Hour > 6
                           select DateTime.Parse(nl.CreateDate).Hour.ToString()
                           ).ToArray();

    var groupedLeads = logNumbers.GroupBy(x => x)
              .Select(x => new { Number = x.Key, Times = x.Count() })
              .ToList();

    //groupedLeads.Add(new { Number = "0", Times = 1 });
    //groupedLeads.Add(new { Number = "1", Times = 1 });
    //groupedLeads.Add(new { Number = "2", Times = 1 });
    //groupedLeads.Add(new { Number = "3", Times = 1 });
    //groupedLeads.Add(new { Number = "4", Times = 1 });
    //groupedLeads.Add(new { Number = "5", Times = 1 });

Answer 1

您可以使用 Enumerable.Range 获取 24 小时序列，无需 GroupBy:

var hourlyLeads = Enumerable.Range(0, 24)
    .Select(h => new 
    { 
        Hour = h, 
        Count = newLeads.Count(nl => nl.CreateDate.Hour == h) 
    })
    .Select(x => new 
    { 
        Number = x.Hour, 
        Times = x.Count == 0 ? 1 : x.Count
    })
    .ToList();

---

更新

How could I set the 'current hour' to '1' as well ? I don't want to show the current hour in progress. I could try to delete it from the collection after the linq statement but was wondering if it was easy to do in the current linq statement

不太清楚，但如果你想排除当前时间:

var hourlyLeads = Enumerable.Range(0, 24)
    .Where(h => h != DateTime.Now.Hour)
    .Select(h => new ........

如果您只想将当前小时设置为 1:

var hourlyLeads = Enumerable.Range(0, 24)
    .Select(h => new 
    { 
        Hour = h, 
        Count = h == DateTime.Now.Hour ? 1 : newLeads.Count(nl => nl.CreateDate.Hour == h) 
    })
    .Select(x => new .....