Linq 你可以通过谷歌搜索找到一个算法。 VideoID RecordingStarted RecordingEnded =================================================

你可以通过谷歌搜索找到一个算法。

    VideoID       RecordingStarted         RecordingEnded
    ==============================================================
    abc123        2013-03-01 15:30:00      2013-03-01 15:40:00        
    def123        2013-03-06 12:00:00      2013-03-06 12:40:00
    ijk123        2013-03-10 11:00:00      2013-03-10 11:05:00
    klm123        2013-03-12 10:05:00      2013-03-12 10:25:00
    And list goes on .......
    .......................
    .............................

    Mar 1, 2013     Mar 8, 2013      Mar 15, 2013     Mar 22, 2013
   ================================================================
   500              300              350              200

//local data for testing
var data = new[] {
    new {VideoId = "abc123",RecordindStarted = DateTime.Parse("2013-03-01 15:30:00"),RecordingEnded = DateTime.Parse("2013-03-01 15:40:00")},        
    new {VideoId = "def123",RecordindStarted = DateTime.Parse("2013-03-06 12:00:00"),RecordingEnded = DateTime.Parse("2013-03-06 12:40:00")},
    new {VideoId = "de1223",RecordindStarted = DateTime.Parse("2013-03-06 12:30:00"),RecordingEnded = DateTime.Parse("2013-03-06 12:50:00")},
    new {VideoId = "ijk123",RecordindStarted = DateTime.Parse("2013-03-10 11:00:00"),RecordingEnded = DateTime.Parse("2013-03-10 11:05:00")},
    new {VideoId = "klm123",RecordindStarted = DateTime.Parse("2013-03-12 10:05:00"),RecordingEnded = DateTime.Parse("2013-03-12 10:25:00")},
    new {VideoId = "klm123",RecordindStarted = DateTime.Parse("2013-03-12 10:05:00"),RecordingEnded = DateTime.Parse("2013-03-13 10:25:00")},
};


var calendar = new GregorianCalendar();

var ungroupedTotalHours = data.Select(d => GetHoursPerDays(d.RecordindStarted, d.RecordingEnded));

var groupedTotalHours = 
         ungroupedTotalHours.SelectMany(v => v)
                            .GroupBy(v=> v.Key)
                            .ToDictionary(v => v.Key, v => v.Sum(val => val.Value));

var result = 
 groupedTotalHours.GroupBy(v =>calendar.GetWeekOfYear( v.Key, CalendarWeekRule.FirstDay, DayOfWeek.Monday))
                  .ToDictionary(v => "Week "+ v.Key, row => row.Sum(val => val.Value));

Console.WriteLine ( string.Join(Environment.NewLine, result.Select(r => r.Key +" has "+r.Value+" hours")) );

public IDictionary<DateTime, int> GetHoursPerDays(DateTime start, DateTime end)
{
    if(end.Date == start.Date)
        return new Dictionary<DateTime, int>{{start.Date, (end -  start).Minutes}};
    return Enumerable.Range(1, (int)(end -  start).TotalHours)
                    .Select(v => start.AddHours(v))
                    .GroupBy(v => v.Date)
                    .ToDictionary( v => v.Key, r => r.Count());
}

Week 9 has 10 hours
Week 10 has 65 hours
Week 11 has 44 hours