How to override the textbox content in CSWPFAutoCompleteTextBox - wpf-controls

Question

I am using the autocomplete textbox from this MSDN link.
Question:
CSWPFAutoCompleteTextBox has property "AutoSuggestionList" which I bound this to observable string collection. Each string is made of id + description. When user selects an item from dropdown, how can I override the texbox content? I want to manipulate the text box content.
This is a textbox that extends a wpf combobox to make it searchable.
When the user types in a string in the textbox, it displays matching strings as a dropdown, user selects an item and the item is displayed in the textbox.
the question is how to override the textbox contents of this control.

Answer 1

Without actual format of your code it is hard to answer precisely, but for example, if your strings are
string[] suggestions = {"0: Yes", "1: No", "666: whatever"}
Then you could get the number by something like
sugestedString.Substring(0, sugestedString.IndexOf(':'));
EDIT: I misunderstood the question. So if I now understands correctly, you might do it with
for(int i = 0; i < suggestions.Length; i++) {
if(suggestions[i] == selectedString) {
return i;
}
}
If you seek only a number within your list of all possible suggestions.
If you seek a number within narrowed-down suggestions, it gets somewhat more difficult.
You firstly need to note down what user has typed so-far (e.g. "Aut"). Then you need what he actually selected (e.g. "Automotive"). With those things, you can then search all your possible suggestions, count how many of them satisfies the user-typed beginning and finaly which of them is the selected one. It might look like this:
int counter=0;
for(int i = 0; i < suggestions.Length; i++) {
if( suggestions[i].StartsWith(typedString)) {
counter++;
if(suggestions[i] == selectedString) {
counter;
}
}
}