Question

I am tring to edit and update my db using gridview itself.I have nearly done everything but my only problem is that i have a dropdown list.I am happy with label for edit and changed it into dropdown list in edit mode.Now i am not able to update the dropdown value alone into my db.I am getting a value called system.web.I am not able to get desired value i am facing difficulty because of literal control.I am a newbie so pls help me out.Thanks in advance mates.
my design:

<asp:GridView runat ="server"  GridLines = "Both" DataKeyNames="book_id"  
 AutoGenerateColumns ="false" CellPadding ="5" CellSpacing ="5" allowpaging="True" allowsorting="True"
 ID="gv_table1" EmptyDataText ="No data exists" OnRowEditing="gv_RowEditing" 
        PageIndex="0" PageSize="10" ToolTip="true"
OnRowCancelingEdit="gv_RowCancelingEdit" OnRowUpdating="gv_RowUpdating" 
        OnRowDeleting="gv_RowDeleting" onpageindexchanging="gv_table1_PageIndexChanging"  
>
<Columns>





<asp:BoundField DataField="book_name"   HeaderText="BookName">
<ControlStyle Width ="60" />
</asp:BoundField>
<asp:BoundField DataField="author_name" HeaderText="Author Name">
<ControlStyle Width ="60" />
</asp:BoundField>
<asp:BoundField DataField="publisher" HeaderText="Publisher">
<ControlStyle Width ="60" />
</asp:BoundField>
<asp:BoundField DataField="year_edition" HeaderText="Year/Edition">
<ControlStyle Width ="60" />
</asp:BoundField>
<asp:BoundField DataField="total_no" HeaderText="Total No">
<ControlStyle Width ="30" />
</asp:BoundField>
<asp:BoundField DataField="available" HeaderText="Available">
<ControlStyle Width ="30" />
</asp:BoundField>
<asp:BoundField DataField="tags" HeaderText="Tags">
<ControlStyle Width ="60" />
</asp:BoundField>
<asp:BoundField DataField="fare" HeaderText="Fare">
<ControlStyle Width ="30" />
</asp:BoundField>
<asp:TemplateField HeaderText="state">
                            <ItemTemplate>
                                <asp:Label ID="drpstatus1" AppendDataBoundItems="True"   Text='<%# Bind("state") %>'   Width ="60" runat="server">

                                </asp:Label >

                            </ItemTemplate>
                            <EditItemTemplate >
                           <asp:DropDownList ID="drpstatus" runat="server"    >
                                <asp:ListItem Text="available" Value="0"></asp:ListItem>
                                <asp:ListItem Text="binding" Value="1"></asp:ListItem>
                                <asp:ListItem Text="lost" Value ="2"></asp:ListItem>
                                <asp:ListItem Text ="notavailable" Value ="3"></asp:ListItem>
                            </asp:DropDownList>


                        </EditItemTemplate>

                            </asp:TemplateField>



 <asp:TemplateField HeaderText ="Options">

                                <itemtemplate >

                                        <asp:linkbutton id="btnEdit" runat="server" commandname="Edit" text="Edit" />

                                        <asp:linkbutton id="btnDelete" runat="server" commandname="Delete" text="Delete" />
                                </itemtemplate>
                                <edititemtemplate>
                                        <asp:linkbutton id="btnUpdate" runat="server" commandname="Update" text="Update" />
                                        <asp:linkbutton id="btnCancel" runat="server" commandname="Cancel" text="Cancel" />
                                </edititemtemplate>
                        </asp:templatefield>





</Columns>
</asp:GridView>

my code behind:

 public void setgrid()
    {

            gv_table1.DataSource = con.GetData("select  book_id,book_name,author_name,publisher,year_edition,total_no,state ,available,tags,fare from book_info where status!='deleted'");
            gv_table1.DataBind();
              }
     protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
    {


        gv_table1.EditIndex = e.NewEditIndex;

        this.setgrid();
        if (!IsPostBack)
        {
            Response.Write("not post back"); 
        }

    }

    protected void gv_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {

        gv_table1.EditIndex = -1;

        this.setgrid();
    }

    public void gv_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {


        string totalno = (gv_table1.Rows[e.RowIndex].Cells[4].Controls[0] as TextBox).Text;
        string available = (gv_table1.Rows[e.RowIndex].Cells[5].Controls[0] as TextBox).Text;
        int total = Convert.ToInt32(totalno);
        int avail = Convert.ToInt32(available);

        if (total < avail)
        {
            Page page = HttpContext.Current.Handler as Page;

            if (page != null)
            {

               string error = "available should not be greater than total no";

                ScriptManager.RegisterStartupScript(page, page.GetType(), "err_msg", "alert('" + error + "');", true);

            }

        }
        else
        {
            int bookid = Convert.ToInt32(gv_table1.DataKeys[e.RowIndex].Values["book_id"].ToString());
            string bookname = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[0].Controls[0])).Text;
            string fare = (gv_table1.Rows[e.RowIndex].Cells[7].Controls[0] as TextBox).Text;


            string authorname = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[1].Controls[0])).Text;
            string publisher = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[2].Controls[0])).Text;
            string yearedition = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[3].Controls[0])).Text;
            string tags = ((TextBox)(gv_table1.Rows[e.RowIndex].Cells[6].Controls[0])).Text;

            string spacediv3 = Convert.ToString (( LiteralControl)(gv_table1.Rows[e.RowIndex].Cells[8].Controls[0])) ;
            string s = spacediv3 ;
            string status = "active";

            con.parameters("@bookid", DBConnection.Type.eInt, bookid);
            con.parameters("@createduser", DBConnection.Type.eVarchar, "user");
            con.parameters("@status", DBConnection.Type.eVarchar, status);
            con.parameters("@bookname", DBConnection.Type.eVarchar, bookname);
            con.parameters("@authorname", DBConnection.Type.eVarchar, authorname);
            con.parameters("@publisher", DBConnection.Type.eVarchar, publisher);
            con.parameters("@yearedition", DBConnection.Type.eVarchar, yearedition);
            con.parameters("@totalno", DBConnection.Type.eInt, totalno);
            con.parameters("@available", DBConnection.Type.eInt, available);
            con.parameters("@tags", DBConnection.Type.eVarchar, tags);
            con.parameters("@fare", DBConnection.Type.eInt, fare);
            con.parameters("@state", DBConnection.Type.eVarchar, s );
            con.parameters("@createddate", DBConnection.Type.eDateTime, "");
            con.parameters("@modifieduser", DBConnection.Type.eVarchar, "");
            con.parameters("@modifieddate", DBConnection.Type.eDateTime, "");

            con.ExecProcedure("sp_books");
            Response.Redirect("book_add.aspx");
        }
    }

    protected void gv_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {

        int bookid = Convert.ToInt32(gv_table1.DataKeys[e.RowIndex].Values["book_id"].ToString());
        string status = "deleted";
        con.parameters("@bookid", DBConnection.Type.eInt, bookid);
        con.parameters("@createduser", DBConnection.Type.eVarchar, "user");
        con.parameters("@status", DBConnection.Type.eVarchar, status);
        con.parameters("@bookname", DBConnection.Type.eVarchar, "");
        con.parameters("@authorname", DBConnection.Type.eVarchar, "");
        con.parameters("@publisher", DBConnection.Type.eVarchar, "");
        con.parameters("@yearedition", DBConnection.Type.eVarchar, "");
        con.parameters("@totalno", DBConnection.Type.eInt, "");
        con.parameters("@available", DBConnection.Type.eInt, "");
        con.parameters("@tags", DBConnection.Type.eVarchar, "");
        con.parameters("@fare", DBConnection.Type.eInt, "");
        con.parameters("@state", DBConnection.Type.eVarchar, "");
        con.parameters("@createddate", DBConnection.Type.eDateTime, "");
        con.parameters("@modifieduser", DBConnection.Type.eVarchar, "");
        con.parameters("@modifieddate", DBConnection.Type.eDateTime, "");

        con.ExecProcedure("sp_books");
        Response.Redirect("book_add.aspx");
    }

Answer 1

Since your DropDownList is inside a TemplateField you can find the reference via FindControl("ID"):

public void gv_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridView gv = (GridView)sender;
    GridViewRow row = gv.Rows[e.RowIndex];
    DropDownList ddlStatus = (DropDownList)row.FindControl("drpstatus");
    String selectedStatus = ddlStatus.SelectedValue;

Side-notes:

1. Use validators instead of postback+alert. On that way you avoid unnecessary postbacks and are able to change the error-layout easily via css.
2. What is con? I hope it’s no a static connection! https://stackoverflow.com/a/9707060/284240
3. You’ve used AppendDataBoundItems for a Label. That works only for List-controls like ListBox or DropDownList.