c# - 展平一个列表，其中一个属性是另一个对象列表

Question

我有以下类(class):

public class Owner
{
    public string Id { get; set; }
    public string Name { get; set; }
}
public class Main
{
    public string Id { get; set; }
    public string Name { get; set; }
    public List<Owner> Owners { get; set; }
}

我要转换List<Main>至 List<FlatList> FlatList 在哪里

public class FlatList
{
        public string Id { get; set; }          // Id from Main
        public string Name { get; set; }        // Name from Main
        public string OwnerId { get; set; }     // Id from each Owner in a Main's Owner
        public string OwnerName { get; set; }   // Name from each Owner in a Main's Owner
}

不幸的是，我无法找到执行此操作的 LinQ 查询。

Answer 1

你应该使用 SelectMany展平一系列主要对象:

Projects each element of a sequence to an IEnumerable and flattens the resulting sequences into one sequence.

因此它将每个 Main 对象投影到 FlatList 对象序列中，然后将结果序列展平为一个 FlatList 序列

var flatList = mainList.SelectMany(m => 
    m.Owners.Select(o => 
        new FlatList { 
              Id = m.Id, 
              Name = m.Name, 
              OwnerId = o.Id,
              OwnerName = o.Name
         })).ToList()