我有一个包含以下值的列表:
<event>
<value1>2013-05-04 10:00:00.123Z</value1>
<value2>1111</value2>
<value3>303533F1700DEE80001E8482</value3>
<value4>IN</value4>
</event>
<event>
<value1>2013-05-04 10:00:00.123Z</value1>
<value2>1111</value2>
<value3>303533F1700DEE80001E8482</value3>
<value4>OUT</value4>
</event>
我需要分组value3值,并获得Distincts value4.
困难之处在于它可以混合使用,与值4一起使用:"OUT, OUT, IN, OUT, IN"。
在Linq中可以这样做吗?!
我明白了:
var s = (from p in trackingList
group p by new {p.value3}
into grp
select new TrackingSteps
{
DateIn = **grp.Key.value1**,
DateOut = 'the **value1** of **value4**'
}).ToList();
我将尝试一个答案,但不完全清楚您想要什么。如果您正在尝试获取一组对象并为每个value3生成单个对象,其中每个生成的对象都具有属性DateIn =(最小value1,其中value4 ="IN")和DateOut =(最大value1,其中value4 ="OUT"),那么它可能看起来像这样:
from p in trackingList
group p by p.Value3 into g
select new {
Value3 = g.Key,
DateIn = g.Where(o => o.Value4 == "IN")
.Select(o => o.Value1)
.DefaultIfEmpty(DateTime.MinValue)
.Min(),
DateOut = g.Where(o => o.Value4 == "OUT")
.Select(o => o.Value1)
.DefaultIfEmpty(DateTime.MaxValue)
.Max()
}
这个LINQ查询按Value3分组,并为每个组选择不同的Value4
var result = trackingList.Descendants("event")
.Select(E => new { Value1 = E.Element("value1").Value,
Value3 = E.Element("value3").Value,
Value4 = E.Element("value4").Value })
.GroupBy(g => g.Value3)
.Select(g => new {
Value3 = g.Key,
//DistintValue4 = g.Select(x => x.Value4).Distinct(),
DateIn = g.Where(x => x.Value4 == "IN").Select(x => x.Value1).FirstOrDefault(),
DateOut = g.Where(x => x.Value4 == "OUT").Select(x => x.Value1).FirstOrDefault()
});