C# 如何合并连续的句点?
有没有一种简单的方法可以合并具有相同值的连续时段(C# 如何合并连续的句点?,c#,algorithm,linq,list,datetime,C#,Algorithm,Linq,List,Datetime,有没有一种简单的方法可以合并具有相同值的连续时段(StartDate)到EndDate 输入: ID开始日期结束日期值 1 2014-01-01 2014-01-31 71 2 2014-02-01 2014-02-28 71 3 2014-03-01 2014-03-31 71 4 2014-04-01 2014-04-30 50,12 5 2014-05-01 2014-05-31 50,12 6 2014-06-01 2014-06-30 7
StartDate
)到EndDate
输入:
ID开始日期结束日期值
1 2014-01-01 2014-01-31 71
2 2014-02-01 2014-02-28 71
3 2014-03-01 2014-03-31 71
4 2014-04-01 2014-04-30 50,12
5 2014-05-01 2014-05-31 50,12
6 2014-06-01 2014-06-30 71
7 2014-08-01 2014-08-31 71(此处跳过一个月)
8 2014-09-01 2014-09-30 71
因此,这些行将按如下方式合并:
- 1、2和3至
01-01-2014 03-31-2014 71
- 4和5至
2014-04-01 05-31-2014 71
- 6将保持不变
- 7和8至
2014-08-01 2014-09-30 71
StartDate-EndDate值
2014-01-01 2014-03-31 71
2014-04-01 2014-05-31 50,12
2014-06-01 2014-06-30 71
2014-08-01 2014-09-30 71
我试过这个:
public List<PeriodInterval> MergePeriods(List<PeriodInterval> samples)
{
var merged = samples.OrderBy(s => s.StartDate)
.ThenBy(s => s.StartDate)
//select each item with its index
.Select((s, i) => new
{
sample = s,
index = i
})
// group by date miuns index to group consecutive items
.GroupBy(si => new
{
date = si.StartDate.AddDays(1),
content = si.Valeur
})
.Select(g => new PeriodInterval
{
StartDate = g.Min(s => s.StartDate),
EndDate = g.Max(s => s.EndDate),
Valeur = g.First().Valeur
});
return merged.ToList();
}
公共列表合并周期(列表示例)
{
var merged=samples.OrderBy(s=>s.StartDate)
.ThenBy(s=>s.StartDate)
//选择每个项目及其索引
.选择((s,i)=>新建
{
样本=s,
指数=i
})
//按日期分组miuns索引以对连续项目进行分组
.GroupBy(si=>新建)
{
日期=si.StartDate.AddDays(1),
content=si.Valeur
})
.选择(g=>new PeriodInterval
{
起始日期=g.Min(s=>s.StartDate),
EndDate=g.Max(s=>s.EndDate),
Valeur=g.First().Valeur
});
返回merged.ToList();
}
创建扩展方法,该方法根据某些条件对序列项进行批处理,检查源序列中的两个序列项:
public static IEnumerable<IEnumerable<T>> SequentialGroup<T>(
this IEnumerable<T> source, Func<T, T, bool> predicate)
{
using(var iterator = source.GetEnumerator())
{
if (!iterator.MoveNext())
yield break;
List<T> batch = new List<T> { iterator.Current };
while (iterator.MoveNext())
{
if (!predicate(batch[batch.Count - 1], iterator.Current))
{
yield return batch;
batch = new List<T>();
}
batch.Add(iterator.Current);
}
if (batch.Any())
yield return batch;
}
}
查询:
var query = items.SequentialGroup((a, b) =>
a.Value == b.Value && (b.StartDate - a.EndDate).Days <= 1)
.Select((g,i) => new Item {
Value = g.First().Value,
StartDate = g.Min(f => f.StartDate),
EndDate = g.Max(f => f.EndDate),
Line = String.Format("mergedLine_{0}", i + 1)
});
你试过什么吗?显示您的尝试。我已尝试将具有相同索引的时段分组
public class Item
{
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public string Value { get; set; }
public string Line { get; set; }
}
var query = items.SequentialGroup((a, b) =>
a.Value == b.Value && (b.StartDate - a.EndDate).Days <= 1)
.Select((g,i) => new Item {
Value = g.First().Value,
StartDate = g.Min(f => f.StartDate),
EndDate = g.Max(f => f.EndDate),
Line = String.Format("mergedLine_{0}", i + 1)
});
[
{
StartDate: "2014-01-01T00:00:00",
EndDate: "2014-03-31T00:00:00",
Value: "71",
Line: "mergedLine_1"
},
{
StartDate: "2014-04-01T00:00:00",
EndDate: "2014-05-31T00:00:00",
Value: "50,12",
Line: "mergedLine_2"
},
{
StartDate: "2014-06-01T00:00:00",
EndDate: "2014-06-30T00:00:00",
Value: "71",
Line: "mergedLine_3"
},
{
StartDate: "2014-08-01T00:00:00",
EndDate: "2014-09-30T00:00:00",
Value: "71",
Line: "mergedLine_4"
}
]