Error while binding data in GridView through Row Bound Event - asp.net

Question

I have following gridview in aspx page:
<asp:GridView Runat="server" id="gv1" PageSize="20" Visible="False" AllowPaging="True" Width="100%"
CssClass="clsDataGrid" AutoGenerateColumns="false" DataKeyNames="intProofSLNo,txtAdminRemarks" CommandArgument='Eval(intProofSLNo,txtAdminRemarks)'
OnRowCommand="gv1_RowCommand" OnRowDataBound ="gv1_OnRowDataBound" >
<asp:BoundField DataField="intProofSLNo" ReadOnly="True" Visible="false" ItemStyle-Wrap="false" HeaderText="Sl No" ItemStyle-CssClass="clsNormalText"></asp:BoundField>
<asp:TemplateField HeaderText="Action">
<ItemTemplate>
<asp:LinkButton ID="lnkbtnApprove" runat="server" CommandName="Approve" Text= "Approve / " />
<asp:LinkButton ID="lnkbtnReject" runat="server" CommandName="Reject" Text= "Reject" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Admin Remarks">
<ItemTemplate>
<asp:Label ID="lblAdminRemarks" runat="server" ItemStyle-Wrap="True" Text='<%# Bind("txtAdminRemarks")%>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtAdminRemarksEdit" runat="server" cssclass=clsCommonInput MaxLength="252" Text='<%# DataBinder.Eval(Container.DataItem, "txtAdminRemarks")%>'></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Edit">
<ItemTemplate>
<asp:LinkButton ID="lblEdit" runat="server" Text="Edit" ToolTip="Edit" CommandName="Edit" CommandArgument='<%# Container.DataItemIndex %>'>
</asp:LinkButton>
</ItemTemplate>
<EditItemTemplate>
<asp:LinkButton ID="lnkUpdate" Width="38" runat="server" Text="Update|" CommandName="Update"CommandArgument='<%# Container.DataItemIndex %>' CausesValidation="true" ToolTip="Save"> </asp:LinkButton>
<asp:LinkButton ID="lnkCancel" runat="server" Width="40" Text="Cancel" CommandName="Cancel"
CausesValidation="false" ToolTip="Reset"></asp:LinkButton>
</EditItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
The user clicks on the 'Edit' link which makes 'Update' and 'Cancel' links visible.It then enters the remarks in the textbox and clicks 'Update'.A row command event is fired which updates the remarks in DB for the entry in that particular row. The same event calls the bind function:
Protected Sub gv1_RowCommand(sender As Object, e As GridViewCommandEventArgs)
If e.CommandName = "Update" Then
//some code to update remarks//
gv1.EditIndex = -1
subBindDataGrid()
End If
The subBindDataGrid() fires the following rowbound event which hides the buttons depending on admin remarks:
Protected Sub gv1_OnRowDataBound(sender As Object, e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.DataRow Then
Dim lblAdminRemarks As Label = DirectCast(e.Row.FindControl("lblAdminRemarks"), Label)
Dim lnkReject As LinkButton = DirectCast(e.Row.FindControl("lnkbtnReject"), LinkButton)
Dim lnkApprove As LinkButton = DirectCast(e.Row.FindControl("lnkbtnApprove"), LinkButton)
Dim lnkEdit As LinkButton = DirectCast(e.Row.FindControl("lblEdit"), LinkButton)
If DataBinder.Eval(e.Row.DataItem, "txtAdminRemarks").ToString().Trim = "Auto-Approved" Then
lnkApprove.Visible = False
lnkReject.Visible = False
lnkEdit.Visible = False
Else
lnkbtnApprove.Visible = True
lnkbtnReject.Visible = True
End If
End If
The remarks get updated in the DB. However, there is some issue in binding and instead of displaying the grid, the page is redirected to an error page. There is no exception thrown anywhere while debugging. The same events are also called in 'Edit'command. However, the functionality works fine there.Please suggest if there is anything wrong with the syntax.

Answer 1

I see you don't define a DataSourceID on the GridView static definition, please make sure you define a DataSource for the GridView in the subBindDataGrid procedure, otherwise it will have a null datasource in input.