对列表列表进行排序C＃

Question

I have the following list of lists that I wish to sort by price:

List<object> StationList = new List<object>();
List<object> ListEntry = new List<object>();

ListEntry.Add(Name);  //string
ListEntry.Add(Area);  //string
ListEntry.Add(Price); //int

StationList.Add(ListEntry);

I have tried to sort it with:

List<object> SortedList = StationList.OrderBy(list => list[2]);

This gives me the error:

//Cannot apply indexing with [] to an expression of type 'object'

How do I sort this list of lists?

Answer 1

As pointed out in the comments, using a List<object> is a bad idea. Especially when used as a container for data that could (and should) be kept in a better structure.

It looks like your StationList should actually be a list of stations. So it would be a good idea to create a structure that describes a station. Maybe something like this:

public class Station
{
    public string Name { get;set; }
    public string Area { get;set; }
    public int Price { get;set; } /* although 'decimal' might be a better type */
}

Now the StationList can be defined and initialized as:

List<Station> StationList = new List<Station>();
/* although you could just call it 'Stations' */

Now create a new Station and fill it with data and add it to the StationList :

Station station = new Station();
station.Name = Name;
station.Area = Area;
station.Price = Price;

StationList.Add(station);

And if you want to order the list of stations by price, you can do it like:

List<Station> SortedList = StationList.OrderBy(entry => entry.Price).ToList();

Which (imho) is more readable than list => list[2] . Also, the whole thing is type safe, which means that you can be sure, that StationList will only contain instances of type Station (or types derived of Station ) and you can access the Name , Area and Price properties of those instances directly, without having to cast them from type Object or having to remember which "property" is at which index in the list.

And if your going to work with the Station informations further, I'd guess you'll have a much easier time if you're using that class instead of List<object> .