如何按属性汇总对象列表

Question

我有“客户”对象列表，我的目标是总结该客户支付了多少钱。

class Customer
{
   public string Name {get; set;}
   public int Paid {get; set;}
}

例如，如果列表包含以下内容：

[{"Bob",90},{"Tom",120},{"Bob",120,{"Alex",67},{"Tom",40}}]

那么预期结果应该是

[{"Bob",210},{"Tom",160},{"Alex",67}}]

这是我的清单

List<Customer> customers = ...

如何实现

Answer 1

List<Customer> customers = ...

var summarized = customers
    .GroupBy( c => c.Name )
    .Select( grp => new
    {
        Name  = grp.Key,
        Total = grp.Sum( c => c.Paid )
    } )
    .OrderByDescending( s => s.Total )
    .ToList();