LINQ - c＃flatten collection to dictionary

Question

我有以下数据结构：

class customer
{
      List<string> photoIds;
      string fullname;
}

样品采集：

新客户（）{new [] {＆＃34; 1＆＃34;，＆＃34; 2＆＃34;，＆＃34; 3＆＃34;}，＆＃34;客户1＆＃34;} ;

新客户（）{new [] {＆＃34; 5＆＃34;，＆＃34; 8＆＃34;，＆＃34; 10＆＃34;}，＆＃34;客户2＆＃34;} ;

新客户（）{new [] {＆＃34; 3＆＃34;，＆＃34; 11＆＃34;，＆＃34; 4＆＃34;}，＆＃34;客户3＆＃34;} ;

我想要实现的是将以下数据转换为Dictionary，其中key是photoid，值是fullname

{1, Cust 1}
{2, Cust 1}
{3, Cust 1}
{5, Cust 2}
{8, Cust 2}
{10, Cust 2}
{3, Cust 3}
{11, Cust 3}
{4, Cust 3}

有什么帮助？

Answer 1

您可以使用SelectMany和ToDictionary可枚举方法执行此操作： -

var result = customers.SelectMany(x => x.photoIds, (custObj, photoIds) => 
                                                         new { 
                                                                 custObj, photoIds 
                                                             })
                     .ToDictionary(x => x.photoIds, x => x.custObj.fullname);

Working Fiddle