在LINQ C＃从数据库中选择数据后如何获得通过编号的顺序排列输出

Question

我有integers ids列表，从表中我只需要为那些ID在列表中，I have already done that选择的细节，但我需要一个data sorted same way as they were in the list Explaination below:

现在

List<int> SelectedUser = new List<int> { 26,1,22,27 }; 
List<ValidateDropDownBind> objValidateUserList = (from p in context.tblUser 
                    join q in context.tblTaskReportingAuthority on p.UserID equals q.UserID into gj 
                    from r in gj.DefaultIfEmpty() 
                    where p.IsActive == true && p.CompanyID == CurrentAdminSession.CompanyID && SelectedUser.Contains(p.UserID) 
                    //orderby r.TaskReportingAuthorityID 
                    select new ValidateDropDownBind 
                    { 
                     value = p.UserID, 
                     name = p.FirstName + " " + p.LastName 
                    }).GroupBy(x => x.value, (key, group) => group.FirstOrDefault()).ToList(); 

，因为我运行此查询我得到的从数据库的详细信息列表中，但它是在sorted form but i need to sort them by the form which they were在list (SelectedUser).

Answer 1

这是不是太漂亮，但你可以使用你的第一个列表，然后从第二选择列表与FirstOrDefault。

最后Where是要确保你不包含空值，如果第一SelectedUser没有在objValidateUserList列表中找到。

var sortedList = SelectedUser.Select(
     sortedListUser => objValidateUserList.FirstOrDefault(nonSortedListUser => nonSortedListUser.value == sortedListUser)) 
     .Where(x => x != null); 

希望它有帮助！