1. Using Skip() and Take() 的普通方法(效率更高，linq需要迭代每个元素)
using System;
using System.Linq;
using System.Collections.Generic;
public static class Extensions
{
public static IEnumerable<IEnumerable<T>> Split<T>(this T[] arr, int size)
{
for (var i = 0; i < arr.Length / size + 1; i++) {
yield return arr.Skip(i * size).Take(size);
}
}
}
public class Example
{
public static void Main()
{
int[] arr = { 1, 2, 3, 4, 5 };
int size = 2;
var arrays = arr.Split(size);
foreach (var array in arrays) {
Console.WriteLine(String.Join(", ", array));
}
}
}
2. Using Skip() and Take() 的Linq select
using System;
using System.Linq;
using System.Collections.Generic;
public static class Extensions
{
public static IEnumerable<IEnumerable<T>> Split<T>(this T[] arr, int size)
{
return arr.Select((s, i) => arr.Skip(i * size).Take(size)).Where(a => a.Any());
}
}
public class Example
{
public static void Main()
{
int[] arr = { 1, 2, 3, 4, 5 };
int size = 2;
var arrays = arr.Split(size);
foreach (var array in arrays) {
Console.WriteLine(String.Join(", ", array));
}
}
}
3. Using Enumerable.GroupBy Method
using System;
using System.Linq;
public class Example
{
public static void Main()
{
int[] arr = { 1, 2, 3, 4, 5 };
int size = 2;
int i = 0;
int[][] arrays = arr.GroupBy(s => i++ / size).Select(s => s.ToArray()).ToArray();
foreach (var array in arrays) {
Console.WriteLine(String.Join(", ", array));
}
}
}
具体迭代过程是这样，我们常规的GroupBy是迭代元素的属性参加分组结果，比如按照每个同学的班主任分组，这里迭代元素s本身没有参与分组属性，而是借助了外部的一个变量i来生成评判结果，用这个结果来对所迭代的元素分组
s->1 i=0 i++/2 = 0
s->2 i=1 i++/2 = 0
s->3 i=2 i++/2 = 1
s->4 i=3 i++/2 = 1
s->5 i=4 i++/2 = 2
