LINQ

Question

我正在尝试使用LINQ对项目列表进行分组，以便在转发器中显示。我有一个查询，几乎可以做我需要的但不完全。

我的数据看起来像

Cart object 
{ID: 10, isInventory: True, Pricing: 4},
{ID: 10, isInventory: True, Pricing: 20},
{ID: 10, isInventory: False, Pricing: 5},
{ID: 10, isInventory: False, Pricing: 23},
{ID: 74, isInventory: False, Pricing: 7}

我希望按isInventory分组，然后按ID分组。目前我有一个接近但仍然不正确的查询。

var grouped = from cart in shoppingCart.Cart
                      group cart by cart.IsInventoryStorage into Cart1
                      from CartGroup in
                          (from cart in Cart1
                           group cart by cart.BranchID)
                      group CartGroup by CartGroup.Key;

看起来它已正确分组，但isInventory上的Keys，我理想地希望它为key.isInventory，然后每个组按key.ID排序

谢谢

Answer 1

这可以在查询语法中使用orderby来完成。请注意，后续排序条件通过逗号分隔。

void Main()
{
    var cart = new List<Cart>();

    cart.Add(new Cart { ID = 10, isInventory = true, Pricing = 4 });
    cart.Add(new Cart { ID = 10, isInventory = true, Pricing = 20});
    cart.Add(new Cart { ID = 10, isInventory = false, Pricing = 5});
    cart.Add(new Cart { ID = 10, isInventory = false, Pricing = 23});
    cart.Add(new Cart { ID = 74, isInventory = false, Pricing = 7});

    var grouped = from c in cart
                  orderby c.isInventory, c.ID
                  select c;

    grouped.Dump();
}

public class Cart
{
    public int ID { get; set; }
    public bool isInventory { get; set; }
    public int Pricing { get; set; }

}

这样输出数据：

10 False 5 
74 False 7 
10 False 23 
10 True 4 
10 True 20 

Answer 2

var cart=new []{
    new {ID= 10, isInventory= true, Pricing= 4},
    new {ID= 10, isInventory= true, Pricing= 20},
    new {ID= 10, isInventory= false, Pricing= 5},
    new {ID= 10, isInventory= false, Pricing= 23},
    new {ID= 74, isInventory= false, Pricing= 7}
};

var results=cart.GroupBy(c=>c.isInventory)
    .SelectMany(grp1=>grp1.GroupBy(th=>th.ID),(grp1,grp2)=>new {grp1=grp1,grp2=grp2})
    .GroupBy(temp0=>temp0.grp1.Key,temp0=>temp0.grp2)
    .Dump();

结果：