Asp.net GridView - Getting row identifier - asp.net

Question

I have a page that displays orders in GridView and each row has a details- and delete-button. Most of the time everything works fine, but if new order arrives between the page refresh and button clicking, wrong order is processed.
I save unique identifier to CommandArgument, but it seems that the identifier in question isn't passed back to server, but instead some kind of counter (e.g. 5th order) and since after the arrival of new order the right one would be 6th, everything goes wrong... What's up with that?
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" PageSize="20"
EnableViewState="False" EnableSortingAndPagingCallbacks="True"
DataSourceID="ldsOrders" AllowPaging="True"
ondatabound="gvOrders_DataBound" CssClass="Gridview" >
<Columns>
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False"
ReadOnly="True" SortExpression="ID" />
<asp:TemplateField>
<ItemTemplate>
<asp:Button ID="btnDelete" runat="server" CommandArgument='<%#Eval("ID") %>' CommandName="Delete"
Text="Delete" OnClick="btnDelete_Click" CausesValidation="False" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Button ID="btnOrder" runat="server" CommandArgument='<%#Eval("ID") %>' CommandName="Order"
Text="Order" OnCommand="btnOrder_Click" CausesValidation="False" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Code-Behind:
protected void btnDelete_Click(object sender, CommandEventArgs e)
{
string orderID = (string)e.CommandArgument;
da.DeleteOrder(Convert.ToInt32(orderID));
Response.Redirect(Request.RawUrl, false);
}

Answer 1

Without any code examples here is something to try...
Assuming that ID is the primary key - you should set that in the GridView DataKeys property. You should not place primary keys in a viewable area.
Where you specify the CommandArgument: that should be the rowindex that is set in the RowDataBound event such that:
//(note this is pseudo-code, but you should get the basic idea)
if( e.row.rowtype == datarow )
{
Button btn = (Button) e.row.findcontrol("btnDelete") ;
btn.CommandArgument = e.row.rowIndex ;
}
And in the delete click event obtain the primary key from the gridview datakeys:
protected void btnDelete_Click(object sender, CommandEventArgs e)
{
int orderIDIdx = (Convert.ToInt32(e.CommandArgument);
int pkey = Convert.ToInt32(Gridview1.Datakeys(orderIDidx).value
da.DeleteOrder(pkey);
Response.Redirect(Request.RawUrl, false);
}
Obviously, add appropriate error checking where applicable.

Answer 2

You should set the DataKeyNames
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.datakeynames.aspx
<asp:GridView ID="Gridview1" DataKeyNames="ID" .... >
then the command delete trigger the RowDeleting event
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.rowdeleting.aspx
which can be used to delete the row using e.Keys[0] to retrieve the id
protected void Gridview1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
Int orderID = Convert.ToInt32(e.Keys[0].ToString());
da.DeleteOrder(Convert.ToInt32(orderID));
}