special characters in Autocomplete c#

I'm using c# and a database in SQL Server. I have an autocomplete field that works fine with norma开发者_运维问答l characters. I would like to add the functionality of autocomplete special characters too, as ö, Ä, é, è, ... I would also like to add the possibility to identify characters that may sound similar in some languages, as 'b' and 'v', so if I type 'boor' would find 'voor' as a possible suggestion.

Any ideas?

Thanks

Edit: The autocomplete textboxes are used for names and surnames (one for each). They are made with AutoCompleteStringCollection. They search in the database for names or surnames that already exist. This part of the application basically gives to the user the possibility to add new persons in the application (name,surname,etc). The goal is that when the user is creating a new person in the application, he/she will get a list with the persons with a similar name or surname to the one he/she is typing in. So if we already have 'James Smith' in the database, when the user is typing Smyth, he/she should get the possibility to change to Smith (as a autocomplete, maybe), saying "hey, do you mean 'Smith'?" So we avoid that the user creates the same person with wrong names.

Because we are working with names and surnames from people from all over the world, the errors in the creation of a new person can come from any language.

PD:

1. would it be a good idea to create my own autocomplete? hiding/showing a listbox right under the textbox

2. For what I'm trying, the function SOUNDEX works really good for characters like ö, Ä, é, è, ... But I can't call the database for every single name or surname. So I don't know well how to use use it.

I am not sure what do you mean by autocompletion. Regarding the second part of your question, you probably need a SQL Server feature SOUNDEX. It returns four-character (SOUNDEX) code to evaluate the similarity of two strings.

Use it like:

SELECT SOUNDEX ('Smith'), SOUNDEX ('Smythe');

Above words are spelled almost identically so they have the same soundex'es S530 and S530. I think the soundex may be used with various languages, though I am not totally sure.

Unfortunately you can use as AutoCompletionSource only a AutoCompleteStringCollection.

But the logic, what will be presented to the user (the box with the matching items below the textbox itself) is fully controlled by the TextBox and can't be influenced in any way.

So even if you use something like SoundEx() or Levenstein Distance, you can't tell it the TextBox, cause it always makes a String.StartsWith() on the given collection and on a selection it replaces the whole content by the select value from the source.

That's something that already drove me crazy. You simply can't really influence what items from the list will be presented to the user and you can't influence what happens if some item from the box is selected.

I would look into Levenshtein distance.

Soundex is rather primitive. It was originally developed to be hand calculated. It results in a key and works well with western names and surnames.

Levenshtein distance looks at two string values and produces a value based on their similarity. It's looking for missing or substituted letters(no phonetic comparison as SoundEx).

Wikipedia reference: http://en.wikipedia.org/wiki/Levenstein_distance

Website for testing two string values using Levenshtein distance: http://gtools.org/levenshtein-calculate.php