.Net 拼字符串

public 
  UserPreferenceViewModel 
  UserProfile(
  string
 
UserPreferenceViewModel profile
  =
  null;
 
 
var query 
  =
  from u 
  in 
  _context.
  Users
 
where 
  u.
  UserName
  == 
  userName
 
select 
  u
 
 
if (
  query.
  Any())
 
 

  {
 
 
var queryFirst 
  = 
  query.
  First();
 
 
UserPreferenceViewModel vm
  = 
  new 
  UserPreferenceViewModel()
 
 

  {
 
 
FirstName 
  =
  queryFirst.
  FirstName,
 
 
LastName 
  =
  queryFirst.
  LastName,
 
 
PlantCode 
  =
  queryFirst.
  PlantCode
 

  };
 
 
profile 
  =
  vm;
 
 
else{
 
 
throw 
  new
  Exception(
  $"Can't found user preference for{
  userName
  }.");
 
 

  // 这种比那种 + '' + 的效率高多了
 
 

  }
 
 
return 
  profile;
 
 

  }