How to Add Additional Element to GridView Pager without PagerTemplate

PagerTemplate allows to create any configuration of pager but it also requires custom paging to be implemented. Sometimes built-in paging completely meet all needs but a little modification is reduired, for example, ability to change page size. That can be done within RowCreated event handler.

<asp:GridView ID="GridView1" runat=server AllowPaging="True" OnRowCreated="GridView1_RowCreated" ...

Code behind:

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.Pager)
    {
        DropDownList ddl = new DropDownList();
        //adds variants of pager size
        ddl.Items.Add("5");
        ddl.Items.Add("10");
        ddl.AutoPostBack = true;
        //selects item due to the GridView current page size
        ListItem li = ddl.Items.FindByText(GridView1.PageSize.ToString());
        if (li != null)
            ddl.SelectedIndex = ddl.Items.IndexOf(li);
        ddl.SelectedIndexChanged += new EventHandler(ddl_SelectedIndexChanged);
        //adds dropdownlist in the additional cell to the pager table
        Table pagerTable = e.Row.Cells[0].Controls[0] as Table;
        TableCell cell = new TableCell();
        cell.Style["padding-left"] = "15px";
        cell.Controls.Add(new LiteralControl("Page Size:"));
        cell.Controls.Add(ddl);
        pagerTable.Rows[0].Cells.Add(cell);
    }
}
void ddl_SelectedIndexChanged(object sender, EventArgs e)
{
    //changes page size
    GridView1.PageSize = int.Parse(((DropDownList)sender).SelectedValue);
    //binds data source
    GridView1.DataSource = ...;
    GridView1.DataBind();
}

Source code - 1.9 kB