Question

Is it possible to make a DataTable as a AutoCompleteSource in a TextBox? (C#)

Answer 1

Jared is correct – you can’t bind directly without doing some manipulation. Here’s an example of using the LINQ DataSet extensions to retrieve a field as the autocomplete source:

DataTable dtPosts = new DataTable();
using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["StackOverflow"].ConnectionString))
{
    conn.Open();
    using (SqlDataAdapter adapt = new SqlDataAdapter("SELECT TOP 100 Id, Title, Body, CreationDate FROM Posts WHERE Title IS NOT NULL ORDER BY Id", conn))
    {
        adapt.SelectCommand.CommandTimeout = 120;
        adapt.Fill(dtPosts);
    }
}

//use LINQ method syntax to pull the Title field from a DT into a string array...
string[] postSource = dtPosts
                    .AsEnumerable()
                    .Select<System.Data.DataRow, String>(x => x.Field<String>("Title"))
                    .ToArray();

var source = new AutoCompleteStringCollection();
source.AddRange(postSource);
textBox1.AutoCompleteCustomSource = source;
textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;