我有下面的课程指定数据记录
class DataRecord
{
public double MeasuredValue { get; set; }
public DateTime MeasurementDate { get; set; }
}
我想选择一小时（日期无关紧要）范围内的记录，其中记录的数量最大。
例：
预期输出：1，4，5（因为跨度10:50内- 11:50 3进行了测量）
我想出的代码是
List<DataRecord> records = new List<DataRecord>();
var maxRecordsInAnHour = records.GroupBy(x => x.MeasurementDate.Hour)
.Aggregate((g1, g2) => { return g2.Count() > g1.Count() ? g2 : g1; });
当我按属性分组时，此代码返回2和3或1和5（取决于顺序），Hour并且只对具有相同值的记录Hour进行分组。
如何调整代码以获得预期的输出？
我将针对您的问题提出2种解决方案，具体取决于列表的长度。
初始化：
var myList = new List<DataRecord>
{
new DataRecord
{
MeasurementDate = new DateTime(2019, 1, 31, 11, 50, 0)
},
new DataRecord
{
MeasurementDate = new DateTime(2019, 1, 31, 17, 21, 0)
},
new DataRecord
{
MeasurementDate = new DateTime(2019, 1, 31, 17, 59, 0)
},
new DataRecord
{
MeasurementDate = new DateTime(2019, 1, 31, 10, 54, 0)
},
new DataRecord
{
MeasurementDate = new DateTime(2019, 1, 31, 11, 54, 0)
},
};
List<DataRecord> result = new List<DataRecord>();
解决方案1：
var minimumMinutes = myList.Min(x => x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute);
var maximumMinutes = myList.Max(x => x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute);
for (int minutes = minimumMinutes; minutes < maximumMinutes; minutes++)
{
var list = myList.Where(x =>
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute <= minutes + 60 &&
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute >= minutes);
if (result.Count < list.Count())
{
result = list.ToList();
}
}
解决方案2：
foreach (var dataRecord in myList)
{
var minutes = dataRecord.MeasurementDate.Hour * 60 + dataRecord.MeasurementDate.Minute;
var before = myList.Where(x =>
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute >= minutes - 60 &&
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute <= minutes).ToList();
var after = myList.Where(x =>
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute <= minutes + 60 &&
x.MeasurementDate.Hour * 60 + x.MeasurementDate.Minute >= minutes).ToList();
if (before.Count > result.Count ||
after.Count > result.Count)
{
result = before.Count > after.Count ? before.ToList() : after.ToList();
}
}
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