相关疑难解决方法(0)

假设我有一个左外连接:

from f in Foo
join b in Bar on f.Foo_Id equals b.Foo_Id into g
from result in g.DefaultIfEmpty()
select new { Foo = f, Bar = result }

如何使用扩展方法表达相同的任务？例如

Foo.GroupJoin(Bar, f => f.Foo_Id, b => b.Foo_Id, (f,b) => ???)
    .Select(???)

当我需要比较2个列表并生成包含所有唯一项目的第3个列表时,我似乎总是遇到问题.我需要经常执行此操作.

尝试用一个简单的例子重现这个问题.

我错过了什么吗？谢谢你的任何建议

想要的结果

   Name= Jo1 Surname= Bloggs1 Category= Account
   Name= Jo2 Surname= Bloggs2 Category= Sales
   Name= Jo5 Surname= Bloggs5 Category= Development
   Name= Jo6 Surname= Bloggs6 Category= Management
   Name= Jo8 Surname= Bloggs8 Category= HR
   Name= Jo7 Surname= Bloggs7 Category= Cleaning

class Program
{
    static void Main(string[] args)
    {
          List<Customer> listOne = new List<Customer>();
        List<Customer> listTwo = new List<Customer>();

        listOne.Add(new Customer { Category = "Account", Name = "Jo1", Surname = "Bloggs1" });
        listOne.Add(new Customer { Category = "Sales", Name = "Jo2", …