Get old Gridview Row values in the RowUpdating event - asp.net

Question

How do I get the old values in a gridview row in the row_updating event?
I'm using a sqldatasource control to populate the grid and want to write the update code in the RowUpdating event.
There are 10 fields displayed in the grid.
I can get the value of the first field using
string old_Category = e.OldValues[0].ToString();.
But it doesn't work for index items greater than 0. This doesn't work
string old_Category = e.OldValues[1].ToString();
it returns an error message
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
even though there are 10 columns in the grid.
========================================
Here's the gridview markup
<asp:GridView
ID="GridView1"
runat="server"
AutoGenerateColumns="False"
DataSourceID="SqlDataSource1"
BorderWidth="0px"
BorderStyle="None"
Width="100%"
CellPadding="2"
PageSize="25"
OnRowDeleting="ProjectListGridView_RowDeleting"
onrowdatabound="GridView1_RowDataBound"
onrowupdating="GridView1_RowUpdating" onrowediting="GridView1_RowEditing" >
<Columns>
<asp:CommandField ShowEditButton="True" />
<asp:TemplateField HeaderText="WeekEnding" SortExpression="WeekEnding">
<ItemTemplate>
<asp:Label ID="lblWeekEnding" runat="server" Text='<%# Bind("WeekEnding") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Project" SortExpression="Project">
<EditItemTemplate>
<asp:DropDownList
ID="DropDownList1"
runat="server"
DataSourceID="sdsDdlProjectsEdit"
DataTextField="ProjectName"
DataValueField="ProjectID"
AutoPostBack="True" onselectedindexchanged="DropDownList1_SelectedIndexChanged"
>
</asp:DropDownList>
<asp:SqlDataSource
ID="sdsDdlProjectsEdit"
runat="server"
ConnectionString="<%$ ConnectionStrings:ttuser %>"
SelectCommand="SELECT ProjectID,ProjectName FROM dbo.aspnet_starterkits_Projects">
</asp:SqlDataSource>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Project") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Category" SortExpression="Category">
<EditItemTemplate>
<asp:DropDownList
ID="DropDownList2"
runat="server"
DataSourceID="sdsDDL2"
DataTextField="CategoryName"
DataValueField="CategoryID">
</asp:DropDownList>
<asp:SqlDataSource
runat="server"
ID="sdsDDL2"
ConnectionString="<%$ ConnectionStrings:ttuser %>"
SelectCommand="SELECT [CategoryID], [CategoryName],[ProjectID] FROM dbo.aspnet_starterkits_ProjectCategories WHERE ([ProjectID]=#ProjectID)">
<SelectParameters>
<asp:Parameter Name="ProjectID" />
</SelectParameters>
</asp:SqlDataSource>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Bind("Category") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Sun" SortExpression="Sun">
<EditItemTemplate>
<asp:TextBox ID="txtSunEdit" runat="server" Text='<%# Eval("Sun") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblSun" runat="server" Text='<%# Bind("Sun") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Mon" SortExpression="Mon">
<EditItemTemplate>
<asp:TextBox ID="txtMonEdit" runat="server" Text='<%# Eval("Mon") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label4" runat="server" Text='<%# Bind("Mon") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Tue" SortExpression="Tue">
<EditItemTemplate>
<asp:TextBox ID="txtTueEdit" runat="server" Text='<%# Eval("Tue") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label5" runat="server" Text='<%# Bind("Tue") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Wed" SortExpression="Wed">
<EditItemTemplate>
<asp:TextBox ID="txtWedEdit" runat="server" Text='<%# Eval("Wed") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label6" runat="server" Text='<%# Bind("Wed") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Thu" SortExpression="Thu">
<EditItemTemplate>
<asp:TextBox ID="txtThuEdit" runat="server" Text='<%# Eval("Thu") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label7" runat="server" Text='<%# Bind("Thu") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Fri" SortExpression="Fri">
<EditItemTemplate>
<asp:TextBox ID="txtFriEdit" runat="server" Text='<%# Eval("Fri") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label8" runat="server" Text='<%# Bind("Fri") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Sat" SortExpression="Sat">
<EditItemTemplate>
<asp:TextBox ID="txtSatEdit" runat="server" Text='<%# Eval("Sat") %>' Columns="2"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label9" runat="server" Text='<%# Bind("Sat") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
and here is the sqldatasource
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:ttuser %>"
SelectCommand="SELECT
#WeekEnding WeekEnding
,Project
,ProjectID
,Category
,CategoryID
,isnull([1], 0) Sun
,isnull([2], 0) Mon
,isnull([3], 0) Tue
,isnull([4], 0) Wed
,isnull([5], 0) Thu
,isnull([6], 0) Fri
,isnull([7], 0) Sat
from
(select P.ProjectName Project,P.ProjectID, CAT.CategoryName Category,CAT.CategoryID, Datepart(dw, TE.TimeEntryDate) DOW, TE.TimeEntryDuration Hours
FROM
dbo.aspnet_starterkits_TimeEntry TE inner join
dbo.aspnet_starterkits_ProjectCategories CAT on
TE.CategoryID=CAT.CategoryID inner join
dbo.aspnet_starterkits_Projects P on
CAT.ProjectID=P.ProjectID
Where (TE.TimeEntryDate between dateadd(dd, -6, #WeekEnding) and #WeekEnding) AND
TE.TimeEntryUserID=(SELECT UserId FROM dbo.aspnet_Users WHERE UserName=#UserName)) Source
pivot (max(Hours)for DOW in ([1],[2],[3],[4],[5],[6],[7]) ) as pvt" OldValuesParameterFormatString="original_{0}"
<SelectParameters>
<asp:ControlParameter ControlID="WeekEnding2" Name="WeekEnding"
PropertyName="Text" />
<asp:ControlParameter ControlID="UserList" Name="UserName"
PropertyName="SelectedValue" />
</SelectParameters>
</asp:SqlDataSource>

Answer 1

Just set Enableviewstate property to false of gridview you can get new value
Reference:
http://www.codeproject.com/Questions/139076/not-getting-new-entered-values-on-grid-view-row-up

Answer 2

Just a long shot really. Have you tried setting the DataKeyNames property?
<asp:gridview id="GridView1"
...
DataKeyNames="ProjectID"
/>
From msdn
Use the OldValues property
(dictionary) to access the original
values of the fields in the row to
update. This dictionary contains all
fields in the row except the key
fields. The key fields are defined in
the DataKeyNames property of a
GridView control.