对象链接:Distinct + concatation

我有一个对象列表，其中9个属性中有8个经常重复，最后一个属性始终不同。

使用c#和LINQ对对象，我想检索(分组)不同的前8个属性的列表，第9个属性跨组连接…

public class MyClass
{
    public int property1 {get;set;}
    public string property2 {get;set;}
    public string property3 {get;set;}
}

我可能有一个列表，如:

var list1 = new List<myClass>
        {
            new myClass {property1 = 1, property2 = "foo", property3 = "This"},
            new myClass {property1 = 1, property2 = "foo", property3 = "is"},
            new myClass {property1 = 1, property2 = "foo", property3 = "a"},
            new myClass {property1 = 1, property2 = "foo", property3 = "test"},
            new myClass {property1 = 1, property2 = "foo", property3 = "value"},
            new myClass {property1 = 2, property2 = "bar", property3 = "Here's"},
            new myClass {property1 = 2, property2 = "bar", property3 = "a"},
            new myClass {property1 = 2, property2 = "bar", property3 = "second"}
        };

我正在努力编写最高性能的LINQ表达式，它将产生以下对象列表:

{
    {property1 = 1, property2 = "foo", newProperty3 = "This is a test value"},
    {property1 = 2, property2 = "bar", newProperty3 = "Here's a second"}
};

有人介意帮忙吗?

list1.GroupBy(x => new { x.property1, x.property2 })
     .Select(g => new 
                    { 
                      property1 = g.Key.property1, 
                      property2 = g.Key.property2, 
                      newProperty3 = string.Join(" ", g.Select(x => x.property3))
                    });