asp.net中linq查本集合中不包含于另一个集合的元素

	  

		
 代码如下
		
复制代码
	  
	  

		
int[] num0 = { 28, 32, 14 };
int[] num1 = {14,15,16};

	  
	
如上，我想把num0中不包含于num1的元素都找出来，其正确结果应该是28,32。早上看到原来linq可以写多个from字句，之后就想到了这样的写法：

	  

		
 代码如下
		
复制代码
	  
	  

		
int[] num0 = { 28, 32, 14 };
int[] num1 = {14,15,16};

var qq = from n1 in num0
from n2 in num1
where n1 != n2
select n1;

	  
	
结果，我错了，调试了一下才知道自己想当然了。结果如下：

	  

		
 代码如下
		
复制代码
	  
	  

		
int[] num0 = { 28, 32, 14 };
int[] num1 = { 14, 15, 16 };

var bb = from n1 in num0
        where num1.Contains(n1) == false
        select n1;

	  
	
另外，推荐一个工具：LinqPad，我的这个例子就是用linqPad 调试的，上面那个结果显示使用了语句：qq.Dump();

	  

		
 代码如下
		
复制代码
	  
	  

		
public void Linq53() {
    List products = GetProductList();
    List customers = GetCustomerList();
    
    var productFirstChars =
        from prod in products
        select prod.ProductName[0];
    var customerFirstChars =
        from cust in customers
        select cust.CompanyName[0];
    
    var productOnlyFirstChars = productFirstChars.Except(customerFirstChars);
    
    Console.WriteLine("First letters from Product names, but not from Customer names:");
    foreach (var ch in productOnlyFirstChars) {
        Console.WriteLine(ch);
    }
}