你可以使用ThenBy
,并采取第二和第三个孩子。但是,这是不可扩展的,所以它取决于impl的需求。如果您想要更强大的功能,可以执行以下操作。它将适用于这个特定的情况。我要看看我是否能优化它是更通用虽然:)
public static class myExt
{
public static List<Parent> OrderByWithTieBreaker(this List<Parent> parents, int depth = 0)
{
if (depth > parents[0].Children.Count())
return parents;
var returnedList = new List<Parent>();
Func<Parent, int> keySelector = x =>
{
IEnumerable<Child> enumerable = x.Children.OrderBy(y => y.Age).Skip(depth);
if (!enumerable.Any())
return 0; //If no children left, then return lowest possible age
return enumerable.Min(z => z.Age);
};
var orderedParents = parents.OrderBy(keySelector);
var groupings = orderedParents.GroupBy(keySelector);
foreach (var grouping in groupings)
{
if (grouping.Count() > 1)
{
var innerOrder = grouping.ToList().OrderByWithTieBreaker(depth + 1);
returnedList = returnedList.Union(innerOrder).ToList();
}
else
returnedList.Add(grouping.First());
}
return returnedList;
}
}
[TestFixture]
public class TestClass
{
public class Parent { public string Name { get; set; } public List<Child> Children { get; set; } }
public class Child { public int Age {get;set;} }
[Test]
public void TestName()
{
var parents = new List<Parent>
{
new Parent{Name="P3", Children = new List<Child>{new Child{Age=1}, new Child{Age=3}, new Child{Age=6}, new Child{Age=7}}},
new Parent{Name="P4", Children = new List<Child>{new Child{Age=1}, new Child{Age=3}, new Child{Age=6}, new Child{Age=7}}},
new Parent{Name="P2", Children = new List<Child>{new Child{Age=1}, new Child{Age=3}, new Child{Age=6}}},
new Parent{Name="P1", Children = new List<Child>{new Child{Age=1}, new Child{Age=2}, new Child{Age=7}}},
new Parent{Name="P5", Children = new List<Child>{new Child{Age=1}, new Child{Age=4}, new Child{Age=5}}}
};
var f = parents.OrderByWithTieBreaker();
int count = 1;
foreach (var d in f)
{
Assert.That(d.Name, Is.EqualTo("P"+count));
count++;
}
}
可能重复[是否有一个内置的方式来比较的IEnumerable(由它们的元素)?(HTTP:/ /stackoverflow.com/questions/2811725/is-there-a-built-in-way-to-compare-ienumerablet-by-their-elements) –
具体来说,你可以使用像'Compare'这样的方法所以:'parents.OrderBy(p => p.Children.Select(x => x.Age).ToList(),new SequenceComparer'(其中'SequenceComparer .Compare“是该链接处的实现) –