DBReader提供字符串的长度而不是字符串

目前我的问题是，当我运行代码时，它显示了一个数据网格与名称的length，而不是名称本身。任何人得到任何线索，都显得很愚蠢。

List<string> NameList = new List<string>();
string connectionString = "Server = localhost; Database = TestDb; Trusted_Connection = True;";
try
    {
    IDbConnection dbcon;
    using (dbcon = new SqlConnection(connectionString))
    {
        dbcon.Open();
        using (IDbCommand dbcmd = dbcon.CreateCommand())
        {
            string sql = "Select * from people";
            dbcmd.CommandText = sql;
            using (IDataReader reader = dbcmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    string FirstName = (string) reader["ForeName"];
                    NameList.Add(FirstName);
                }
                DataGrid1.ItemsSource = NameList.ToList();
                reader.Close();
                dbcon.Close();
            }
        }
    }
}
catch (Exception ex)
{
    MessageBox.Show(ex.ToString());
}

IList<string> NameList = new List<string>();
DataGrid1.DataSource = NameList.Select(s => new 
                       { 
                           Value = s 
                       }).ToList();