SelectList根本沒有排序

Question

public static SelectList HolidayDays() 
{ 
    SelectList retval = GenerateKeyValueList<HolidayCity>(HolidayCityHelper.GetFriendlyName, HolidayCity.NotSet); 

    //sort 
    retval.OrderBy(i => i.Text == "New York") 
      .ThenBy(i => i.Text == "London") 
      .ThenBy(i => i.Text); 

    return retval; 
} 

爲什麼SelectList沒有排序呢？它保持與我在執行排序操作之前所處的順序完全相同，但它編譯並運行時沒有錯誤。

Answer 1

OrderBy和ThenBy返回一個集合，你沒有設置你的返回值;

---

SelectList retval = GenerateKeyValueList<HolidayCity>(HolidayCityHelper.GetFriendlyName, HolidayCity.NotSet); 

return new SelectList(retval 
     .OrderByDescending(i => i.Text == "New York") 
     .ThenByDescending(i => i.Text == "London") 
     .ThenBy(i => i.Text).ToList(), 
    "Value", "Text");