我的猜测是,这与 LINQ 的惰性评估有关OrderBy
。例如,如果您有:
var things = unsortedThings.OrderBy(foo => foo.Bar);
var quarter = things.Count() / 4;
那么如果foo.Bar
属性不能相互比较,那将完全抛出该异常。
例如:
using System;
using System.Linq;
class Foo {}
class Program
{
public static void Main()
{
var foos = new[] { new Foo(), new Foo() };
var ordered = foos.OrderBy(x => x);
Console.WriteLine(ordered.Count());
}
}
输出:
Unhandled Exception: System.ArgumentException: At least one object must implement IComparable.
at System.Collections.Comparer.Compare(Object a, Object b)
at System.Linq.EnumerableSorter`2.CompareKeys(Int32 index1, Int32 index2)
at System.Linq.EnumerableSorter`1.QuickSort(Int32[] map, Int32 left, Int32 right)
at System.Linq.EnumerableSorter`1.Sort(TElement[] elements, Int32 count)
at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__0.MoveNext()
at System.Linq.Enumerable.Count[TSource](IEnumerable`1 source)
at Program.Main()