我一直认为这两种方法是相似的：
public static IEnumerable<Func<int>> GetFunctions()
{
for(int i = 1; i <= 10; i++)
yield return new Func<int>(() => i);
}
public static IEnumerable<Func<int>> GetFunctionsLinq()
{
return Enumerable.Range(1,10).Select(i => new Func<int>(() => i));
}
然而,当它们转换为List< Func< int>>时,它们产生不同的结果：
List<Func<int>> yieldList = GetFunctions().ToList();
List<Func<int>> linqList = GetFunctionsLinq().ToList();
foreach(var func in yieldList)
Console.WriteLine("[YIELD] {0}",func());
Console.WriteLine("==================");
foreach(var func in linqList)
Console.WriteLine("[LINQ] {0}",func());
输出是：
[YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 [YIELD] 11 ================== [LINQ] 1 [LINQ] 2 [LINQ] 3 [LINQ] 4 [LINQ] 5 [LINQ] 6 [LINQ] 7 [LINQ] 8 [LINQ] 9 [LINQ] 10
为什么是这样？
