C#LINQ计数元素具有不同的

我有一组KeyValuePair项，其中DateTime为键，字符串为值。 基本上，我的数据如下所示：

12/07/2013 - 10220
12/07/2013 - 10220
12/07/2013 - 12220
12/07/2013 - 11240
12/07/2013 - 15220
13/07/2013 - 23220
13/07/2013 - 35620
14/07/2013 - 15620
14/07/2013 - 15620

我想有一个清单，列出我每天有多少项目（不同）。因此，查询将导致：

12/07/2013 - 4
13/07/2013 - 2
14/07/2013 - 1

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使用

分组依据

var dateGrouped = dates.GroupBy(x => x.Key)
                       .Select(x => new { Date = x.Key, Values = x.Distinct().Count() });

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下面是完整示例的解决方案

        var list = new[]
        {
            new {Date = new DateTime(2013,07,12), value = 10220},
            new {Date = new DateTime(2013,07,12), value = 10220},
            new {Date = new DateTime(2013,07,12), value = 12220},
            new {Date = new DateTime(2013,07,12), value = 11240},
            new {Date = new DateTime(2013,07,12), value = 15220},
            new {Date = new DateTime(2013,07,13), value = 23220},
            new {Date = new DateTime(2013,07,13), value = 35620},
            new {Date = new DateTime(2013,07,14), value = 15620},
            new {Date = new DateTime(2013,07,14), value = 15620},
        };


        var res = from l in list group l by new { l.Date } into g select new { g.Key.Date, value = g.Distinct().Count() };

        foreach (var item in res)
        {
            Console.WriteLine(item.Date + " " + item.value);
        }