Linq按产品分类，但显示猫猫

Question

因此，我遇到了一个问题，代码选择了一个类别，我需要更改排序顺序，以便按product.Name排序，然后按category.name排序。

但问题是，我仍然希望选择一个类别，但是如何在不添加额外的联接或选择的情况下，首先按照product.name进行排序。

从类别中选择category.name orderby category.Name //orderby类别名称

稍后，在视图i循环预见(category.products)和传入category.producti以查看显示

但是排序顺序是错误的，顺序总是按Category.Name排序的，我如何先按Product.Name排序，然后再按Category.Name排序？SelectMany会帮忙吗？同样，我不想破坏我的查询的select部分，只是按内容排序。

类产品{公共字符串名{ get；set；} public int CategoryID { get；set；}

类类别{公共字符串名{ get；set；} public int ID { get；set；}

//指定第一个数据源。静态列表类别=新列表(){新类别(){Name=“饮料”，ID=001}，新类别(){Name=“调味品”，ID=002}，新类别(){Name=“蔬菜”，ID=003}，新类别(){Name=“谷物”，ID=004}，新类别(Name=“水果”，ID=005} )

}；

//指定第二个数据源。静态列表产品=新列表(){新产品{Name=“可乐”、CategoryID=001}、新产品{Name=“茶”、CategoryID=001}、新产品{Name=“芥末”、CategoryID=002}、新产品{Name=“泡菜”、CategoryID=002}、新产品{Name=“胡萝卜”、CategoryID=003}、新产品{Name=“Bok Choy”、CategoryID=003}、新产品{Name=“桃”、CategoryID=005}、新产品{Name=“甜瓜”、CategoryID=005}、}；

Answer 1

class Category
{
    public string Name { get; set; }
    public int ID { get; set; }
    public List<Product> products { get; set;}
}

class Product 
{
    public string Name { get; set; }
    public int ID { get; set; }
}


void Main()
{
        // Specify the second data source.
         List<Product> BevProducts = new List<Product>()
        {
            new Product{Name="ZCola"},
        };

        // Specify the third data source.
         List<Product> CondProducts = new List<Product>()
        {
            new Product{Name="Sugar"},
        };
      // Specify the first data source.
     List<Category> categories = new List<Category>()
        { 
            new Category(){Name="Beverages", ID=001, products=BevProducts},
            new Category(){ Name="Condiments", ID=002, products=CondProducts},

        };



        var sortedCats = categories.OrderBy(c => c.products.Min(p => p.Name)).ToList();

        foreach (var category in sortedCats)
        {
            //display category
            System.Console.Out.WriteLine(category.Name);


            //Assuming each category contains exactly one product in the list ie 1 to 1 relationship
            // how can I sort by product.Name, so if ZCola comes before Sugar, ZCola's Category (Beverages) sorts before Condiments
            // so in this Case Beverages, Condiments is the right order, because ZCola comes after Sugar.
            var  sortedProductsPerCategory = category.products.OrderBy(p => p.Name).ToList();

            foreach (var product in sortedProductsPerCategory)
            {
                    //display product
                    System.Console.Out.WriteLine("   " + product.Name);
            }
        }



} 

Answer 2

哦，我看到你的查询，格式很差。

你需要order by Product.Name group by Category.Name

Answer 3

//LinqPad code

class Category
{
    public string Name { get; set; }
    public int ID { get; set; }
    public List<Product> products { get; set;}
}

class Product 
{
    public string Name { get; set; }
    public int ID { get; set; }
}


void Main()
{
        // Specify the second data source.
         List<Product> BevProducts = new List<Product>()
        {
            new Product{Name="ZCola"},
        };

        // Specify the third data source.
         List<Product> CondProducts = new List<Product>()
        {
            new Product{Name="Sugar"},
        };
      // Specify the first data source.
     List<Category> categories = new List<Category>()
        { 
            new Category(){Name="Beverages", ID=001, products=BevProducts},
            new Category(){ Name="Condiments", ID=002, products=CondProducts},

        };



        var sortedCats = categories.OrderBy(c => c.ID).ToList();

        foreach (var category in sortedCats)
        {
            //display category
            System.Console.Out.WriteLine(category.Name);

        //Assuming each category contains exactly one product in the list ie 1 to 1 relationship
// how can I sort by product.Name, so if ZCola comes before Sugar, ZCola's Category (Beverages) sorts before Condiments
// so in this Case Beverages, Condiments is the right order, because ZCola comes after Sugar.
            var  sortedProductsPerCategory = category.products.OrderBy(p => p.Name).ToList();

            foreach (var product in sortedProductsPerCategory)
            {
                    //display product
                    System.Console.Out.WriteLine("   " + product.Name);
            }
        }



}