using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

public partial class GridViewSelect : System.Web.UI.Page

{

    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)

    {

        GridView1.SetRowValueValueByCell(1, DropDownList1.SelectedValue);

    }

}

public static class GridViewExtensions

{

    public static void SetRowValueValueByCell(this GridView GridView, int CellNumber, string CellValue)

    {

        int intSelectedIndex = 0;

        int intPageIndex = 0;

        int intGridViewPages = GridView.PageCount;

        // Loop thru each page in the GridView

        for (int i = 0; i < intGridViewPages; i++)

        {

            // Set the current GridView page

            GridView.PageIndex = i;

            // Bind the GridView to the current page

            GridView.DataBind();

            // Loop thru each row in the GridView

            foreach (GridViewRow GVRow in GridView.Rows)

            {

                // Check to see if the value of GridView cell 2 matches

                // In this example cell 1 (0) is the select link

                if (GVRow.Cells[CellNumber].Text == CellValue)

                {

                    // If it is a mach set the variables and exit

                    intSelectedIndex = GVRow.RowIndex;

                    intPageIndex = i;

                    break;

                }

            }

        }

        // Set the GridView to the values found

        GridView.PageIndex = intPageIndex;

        GridView.SelectedIndex = intSelectedIndex;

        GridView.DataBind();

    }

}