怎么动态创建DataGridView 表头

当查询到数据时，可以显示表头，当无数据时，一片空白。代码如下：
/// <summary>
        /// 读取并绑定生产数据显示
        /// </summary>
        private void BindDataToSmallCodeList()
        {
            try
            {
                // 创建工厂类实例
                BLLFactory.BLLFactory bllFactory = new BLLFactory.BLLFactory();
                // 创建生产管理类实例
                IBLL.ISmallCodeManager SmallCodeManager = bllFactory.BuildSmallCodeManager();                // 调用实例方法
                
                #region 查询条件
                string _CodeName = this.tscbCodeName.ComboBox.SelectedValue.ToString().Trim();
                string _CodeContent = this.tscbContent.ComboBox.SelectedValue.ToString().Trim();
                #endregion
                if (_CodeName != "" || _CodeName != "")
                {
                    _smallCodeCollection = SmallCodeManager.GetSmallCodeInfoByOther(_CodeName, _CodeContent);
                }
                // 如果包含生产信息
                if (_smallCodeCollection.Count > 0)
                {
                    // 绑定生产数据显示
                    BindingSource source = new BindingSource();
                    source.DataSource = _smallCodeCollection.Values;
                    this.dgvSmallCodeList.DataSource = source;                    // 设置中文列名
                    dgvSmallCodeList.Columns["SmallCodeID"].HeaderText = "小代码表ID";
                    dgvSmallCodeList.Columns["SmallCodeID"].ToolTipText = "[只读列]";
                    dgvSmallCodeList.Columns["SmallCodeID"].DisplayIndex = 0;
                    dgvSmallCodeList.Columns["SmallCodeID"].ReadOnly = true;
                    dgvSmallCodeList.Columns["SmallCodeID"].Visible = false;
                    //dgvSmallCodeList.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.ColumnHeader;                    dgvSmallCodeList.Columns["CodeID"].HeaderText = "代码ID";
                    dgvSmallCodeList.Columns["CodeID"].DisplayIndex = 1;
                    dgvSmallCodeList.Columns["CodeName"].HeaderText = "代码名";
                    dgvSmallCodeList.Columns["CodeName"].DisplayIndex = 2;                    dgvSmallCodeList.Columns["CodeSeq"].HeaderText = "代码序号";
                    dgvSmallCodeList.Columns["CodeSeq"].DisplayIndex = 3;                    //dgvSmallCodeList.Columns["Station"].AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells;
                    dgvSmallCodeList.Columns["CodeFatherID"].HeaderText = "父ID";
                    dgvSmallCodeList.Columns["CodeFatherID"].DisplayIndex = 4;                    dgvSmallCodeList.Columns["CodeDesc"].HeaderText = "代码描述";
                    dgvSmallCodeList.Columns["CodeDesc"].DisplayIndex = 5;                    dgvSmallCodeList.Columns["CodeFlag"].Visible = false;
                    
                    dgvSmallCodeList.AllowUserToResizeColumns = true;                    // 设置工具提示
                    foreach (DataGridViewRow dgvRow in dgvSmallCodeList.Rows)
                    {
                        foreach (DataGridViewCell dgvCell in dgvRow.Cells)
                        {
                            if (dgvCell.ReadOnly)
                                dgvCell.ToolTipText = "[只读格]";
                            else
                                dgvCell.ToolTipText = "[可写格]";
                        }
                    }
                }
                else
                {
                    // 绑定生产数据显示
                    BindingSource source = new BindingSource();
                    //source.DataSource = _productCollection.Values;
                    this.dgvSmallCodeList.DataSource = source;                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    ex.Message,
                    "显示数据",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Error);
            }        }
如何修改else中的代码，，，谢谢。。