:GridView空レコード時にHeaderを表示する

public class GridViewEx : GridView

{



    //      Columns   

    private ArrayList _columns;





    [DefaultValue(true)]

    public bool ForceShowHeader

    {

        get

        {

            object o = ViewState["ForceShowHeader"];

            if (o != null)

                return (bool)o;



            return true;

        }

        set

        {

            ViewState["ForceShowHeader"] = value;

        }

    }



    protected override ICollection CreateColumns(PagedDataSource dataSource, bool useDataSource)

    {

        if (_columns != null)

            return _columns;



        _columns = (ArrayList)base.CreateColumns(dataSource, useDataSource);

        return _columns;

    }



    protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)

    {

        int count = base.CreateChildControls(dataSource, dataBinding);



        if (ForceShowHeader && count == 0)

        {

            Table table;

            if (Controls.Count == 0)

            {

                table = CreateChildTable();

                Controls.Add(table);

            }

            else

            {

                table = Controls[0] as Table;

                if (table == null)

                    throw new ApplicationException("         Table   ");

            }



            DataControlField[] fields = new DataControlField[_columns.Count];

            _columns.CopyTo(fields, 0);



            //            

            GridViewRow headerRow = CreateRow(-1, -1, DataControlRowType.Header, DataControlRowState.Normal);

            InitializeRow(headerRow, fields);



            //    RowCreated   

            GridViewRowEventArgs args = new GridViewRowEventArgs(headerRow);

            OnRowCreated(args);



            //           

            table.Rows.AddAt(0, headerRow);

        }



        return count;

    }

}