I am back! meaning more silly qouestions.. 
I have a simple code to populate an AutoCompleteCustomSource with data from a RepositoryList, the problem is that I want to genralize it, use the same function every time:
// tbCompanyType = TextBox
// companyTypeCollection = CompanyTypeCollection : RepositoryList<CompanyType,CompanyTypeCollection>
string[] accs = new string[companyTypeCollection.Count];
for (int i = 0; i < companyTypeCollection.Count; i++)
{
accs = companyTypeCollection.Name;
}
tbCompanyType.AutoCompleteCustomSource.Clear();
tbCompanyType.AutoCompleteCustomSource.AddRange(accs);
This is the function (clearly not working):
public void PopulateAutoComplete(RepositoryList<?, ?> repList, AutoCompleteStringCollection target)
{
string[] accs = new string[repList.Count];
for (int i = 0; i < repList.Count; i++)
{
accs = repList.Name;
}
target.Clear();
target.AddRange(accs);
}