How to solve System.ArgumentOutOfRangeException exception?

Question

I have a grid with several data columns and a column with check boxes. There is a column called app Number which contains numbers. Now I want to select number in the checked rows and put them into an array . How can I do it?

Here is the code I have done up to now.

<asp:GridView ID="gvAppeals" runat="server" BackColor="White" BorderColor="#CC9966" BorderStyle="None" BorderWidth="1px" CellPadding="4"
    Width="665px" AutoGenerateColumns="False" OnSelectedIndexChanged="gvAppeals_SelectedIndexChanged1"
    AllowPaging="True" PageSize="10" OnPageIndexChanging="gvAppeals_PageIndexChanging" OnRowDataBound="gvAppeals_RowDataBound">
    <Columns>
        <asp:BoundField DataField="App_no" HeaderText="APP NO">
            <HeaderStyle HorizontalAlign="Left" />
            <ItemStyle Font-Size="Small" HorizontalAlign="Left" VerticalAlign="Middle" />
        </asp:BoundField>
        <asp:BoundField DataField="EMP_FULLNAME" HeaderText="FULL NAME">
            <HeaderStyle HorizontalAlign="Left" />
            <ItemStyle Font-Size="Small" HorizontalAlign="Left" VerticalAlign="Middle" />
        </asp:BoundField>
        <asp:BoundField DataField="EMP_NIC_NO" HeaderText="NIC">
            <HeaderStyle HorizontalAlign="Left" />
            <ItemStyle Font-Size="Small" HorizontalAlign="Left" VerticalAlign="Middle" />
        </asp:BoundField>
        <asp:BoundField DataField="EMP_BIRTHDAY" HeaderText="BIRTH DATE" DataFormatString="{0:yyyy-MM-dd}">
            <HeaderStyle HorizontalAlign="Left" />
            <ItemStyle Font-Size="Small" HorizontalAlign="Left" VerticalAlign="Middle" />
        </asp:BoundField>
        <asp:TemplateField>
            <%--<HeaderTemplate>
                            <asp:CheckBox ID="chkHeader" runat="server" AutoPostBack="true" />
                        </HeaderTemplate>--%>
            <ItemTemplate>
                <asp:CheckBox ID="chkSelect" runat="server" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    <FooterStyle BackColor="#FFFFCC" ForeColor="#330099" />
    <HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" />
    <PagerStyle BackColor="#FFFFCC" ForeColor="#330099" HorizontalAlign="Center" />
    <RowStyle BackColor="White" ForeColor="Black" />
    <SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="#663399" />
    <SortedAscendingCellStyle BackColor="#FEFCEB" />
    <SortedAscendingHeaderStyle BackColor="#AF0101" />
    <SortedDescendingCellStyle BackColor="#F6F0C0" />
    <SortedDescendingHeaderStyle BackColor="#7E0000" />
</asp:GridView>

C# code

protected void btnConfirm_Click(object sender, EventArgs e)
    {
        //DataSet ds = new DataSet();
        int[] numbers;
        numbers = new int[gvAppeals.Rows.Count];
        int noOfRowsChecked = 0;

        foreach (GridViewRow row in gvAppeals.Rows)
        {
            int rowIndex = row.RowIndex;
            CheckBox chkrow = (CheckBox)row.FindControl("chkSelect");

            if (chkrow.Checked == true)
            {
                numbers[noOfRowsChecked] = Int32.Parse(gvAppeals.DataKeys[rowIndex]["App_no"].ToString());
                noOfRowsChecked++;
            }

            //update the dept by checking the selected appeal numbers 
            if (noOfRowsChecked > 0)
            {
                for (int i = 0; i < numbers.Length; i++)
                {
                    int appNo = numbers[i];
                    dba.confirmAppeal(appNo);
                }
            }
            else
            {
                WebMsgBox.Show("Please select an application to confirm");
            }
        }
    }

Answer 1

Just a gentle reminder that you need to subtract one (-1) on your indexing. That's probably the reason you're getting System.ArgumentOutOfRangeException .

Answer 2

There are no DataKeys defined in the GridView, to it will always be out of range. Add the DataKeyNames property to the GridView.

<asp:GridView ID="gvAppeals" runat="server" DataKeyNames="App_no" >