C# LINQ关联两个List更新数据

//关联更新姓名
(from a in listSalesRank
 join b in listUsers on a.UserId equals b.Account
 select new { a, b }).ForEach(item =>
 {
     item.a.UserName = item.b.UserName;
 });

(from a in listIVs
 join b in listDOs on a.DO_isid equals b.isid
 select new { a, b }).ForEach(item =>
 {
     item.a.Quantity = item.b.Qty;
     item.a.Price = item.b.Price;
     item.a.Amount = item.b.Amount;
 });