Question

我有2个linq语句，它们都完全正常工作。我想知道是否可以将它们混合成一个并在一个linq之后获得正确的列表。

var result = list3.Where(Srodek => list4.Any(x => x == Srodek.Srodek.category1) &&
                                  (Srodek.Srodek.Source.Device == _text || Srodek.Srodek.ID.Device == _text))
                  .ToList();
var list666 = list3.Select(obj => new { obj, dt = DateTime.ParseExact(obj.LeftColumn, dateFormat, CultureInfo.InvariantCulture) })
                   .Where(x => x.dt >= czas11 && x.dt <= czas22)
                   .Select(x => x.obj).ToList();

Answer 1

LINQ方法返回IEnumerable<T>，可以在IEnumerable<T>上运行。

你可以写

sequence.Where(...).Select(...)

Answer 2

一个清单：

var result = list3.Where(obj => {
                              var dt = DateTime.ParseExact(obj.LeftColumn, dateFormat, CultureInfo.InvariantCulture);
                              return (list4.Any(x => x == obj.Srodek.category1) &&
                              (obj.Srodek.Source.Device == _text || obj.Srodek.ID.Device == _text)) ||
                              (dt >= czas11 && dt <= czas22);})       
                  .ToList();

Answer 3

为什么你不能混合它们？ list.where（.........）选择（.......）toList（）;

var result = list3.Where(Srodek => list4.Any(x => x == Srodek.Srodek.category1) &&
                         (Srodek.Srodek.Source.Device == _text || Srodek.Srodek.ID.Device== _text))
                   .Select(obj => new { obj, dt = DateTime.ParseExact(obj.LeftColumn, dateFormat, CultureInfo.InvariantCulture) })
                  .Where(x => x.dt >= czas11 && x.dt <= czas22)
                  .Select(x => x.obj)
                  .ToList();

Answer 4

您可以使用Union加入两个linq查询。

list3.Where(Srodek => list4.Any(x => x == Srodek.Srodek.category1) &&
                              (Srodek.Srodek.Source.Device == _text || Srodek.Srodek.ID.Device == _text))
               .Union(list3.Select(obj => new { obj, dt = DateTime.ParseExact(obj.LeftColumn, dateFormat, CultureInfo.InvariantCulture) })
               .Where(x => x.dt >= czas11 && x.dt <= czas22)
               .Select(x => x.obj));

将两个linq语句混合成一个？

4 个答案: