使用其他列表中的属性创建列表

Question

我有一个包含项目名称和项目所有者的对象列表，如下所示：

[
    {
        project_name:"abc",
        project_duration:"2 weeks",
        contactInfo: [
          {
            name:"john"
          },
          {
            name:"ron"
          },
        ]
    },
    {
        project_name:"def",
        project_duration:"4 weeks",
        contactInfo: [{
            name:"steve"
        }]
    },
    {
        project_name:"xyz",
        project_duration:"9 weeks",
        contactInfo: [{
            name:"john"
        }]
    }
]

如何从上面的列表中为每个用户创建一个包含项目的列表？

[
    {
        name: "john",
        projects:[
            {
                project_name:"abc"
            },
            {
                project_name:"xyz"
            }

        ]   
    }
]

Answer 1

Group基于属性Name的值。
然后选择新对象：
-Name是分组密钥。
-子列表只是旧对象的投影。

data.GroupBy(x => x.contactInfo.name)
    .Select(g =>
        new Result
        {
            name = g.Key,
            projects =
                g.Select(x => new Project_t2
                {
                    project_name = x.project_name,
                    projec_name = x.project_duration
                }).ToList()
        })
        .ToList();

Live Demo