C# 在列表中搜索项目

搜索项目时

person[] prn = 
new person[]
{
 new person { Name = "Robert", RList = 
{new ReceipeList { NameofRecipie = "Coak" },
new ReceipeList { NameofRecipie = "Pizza" }    } },

new person { Name = "Rahim", RList = 
{ new ReceipeList { NameofRecipie = "Coak" },
new ReceipeList { NameofRecipie = "OnionBread" }} },
};

使用

它没有返回任何结果

var query = from lst in prn  where(lst.RList.Contains(lstr) )  select lst;

---

这不起作用，因为您正在搜索ReceipeList的特定实例（通过引用）。因此，您的查询将只返回具有ReceipeList的特定lstr实例的值，而不是具有与您指定的值相同的值的ReceipeList

您可以通过在ReceipeList中重写，或将查询修改为：

 foreach (var v in query)
 {
            Console.Write(v.Name.ToString()+" ordered   :");

            foreach(ReceipeList lst in v.RList)
            {
                Console.Write(lst.NameofRecipie.ToString()+",");
            }
            Console.WriteLine();
 }

---

这是因为它使用（）方法通过谓词搜索ReceipeList实例，而不是搜索特定的实例。

我不确定，但您也可以看看，这是否会有所帮助

 foreach (var v in query)
 {
            Console.Write(v.Name.ToString()+" ordered   :");

            foreach(ReceipeList lst in v.RList)
            {
                Console.Write(lst.NameofRecipie.ToString()+",");
            }
            Console.WriteLine();
 }

string lstr = "Coak";
var query = from lst in prn
            where lst.RList.Any(r => r.NameofRecipie == lstr)
            select lst;