LINQ：什麼是表達式樹的語法交叉連接

Question

如何編寫表達式樹的語法這個LINQ查詢

from x in 100.To(999) 
from y in 100.To(999) 
let product = x * y 
where product.IsEven() 
select product 

Answer 1

的相當於「從X與Y選擇」是用了「的SelectMany」關鍵字一個額外的'選擇'：

100.To(999).SelectMany(x => 100.To(999).Select(y => x * y)) 
.Where(x => x.IsEven())