OrderBy with Swedish letters

问题

I have a list of my custom class Customer and I want to sort them alphabetically by Title. So I wrote

myList = myList.OrderByDescending(x => x.Title).ToList<Customer>();

Now the problem is that this method doesn't support the Swedish way of sorting the letters å, ä, ö. They should appear at the end after the letter z but they don't.

So I made a workaround method that replaces the Swedish letters before the ordering and then changes them back afterwords. It looks like this but it is quite slow. Can somebody think of a better way?

private List<Customer> OrderBySwedish(List<Customer> myList)
    {
        foreach (var customer in myList)
        {
            customer.Title = customer.Title.Replace("å", "zzz1").Replace("ä", "zzz2").Replace("ö", "zzz3").Replace("Å", "Zzz1").Replace("Ä", "Zzz2").Replace("Ö", "Zzz3");
        }

        myList= myList.OrderBy(x => x.Title).ToList<Customer>();

        foreach (var customer in myList)
        {
            customer.Title = customer.Title.Replace("zzz1", "å").Replace("zzz2", "ä").Replace("zzz3", "ö").Replace("Zzz1", "Å").Replace("Zzz2", "Ä").Replace("Zzz3", "Ö");
        }
        return myList;
    }

回答1:

You can use culture specific StringComparer, see here.

CultureInfo culture = new CultureInfo("sv-SE");
var result = myList.OrderByDescending(x => 
               x.Title, StringComparer.Create(culture, false));

回答2:

Set the Thread.CurrentCulture property to the correct culture.

回答3:

I my case: _My sorting list have value was encoded. This make my order incorrect. Add decoded solving my problems !

回答4:

The workaround I found for a somewhat similar problem was to have a secondary field that held the converted version of the data.
In my case, we had person.Name and person.SearchName, where SearchName was Name converted to have no diacritics.

But this was only the best approach (AFAIK) because we wanted a speedy db search/filtering and then instantiating only the relevant results.
If you already have the objects in memory I would advise going with one of the other approaches; and not this one.

来源：https://stackoverflow.com/questions/7229445/orderby-with-swedish-letters

标签

sorting

letters