template field issue in the gridview

Question

Q:

I have the following problem , and i don't know how to fix it really.

I have a grid view one of the columns is a template field as (text box). The grid view consists of 8 rows . What i do is every time the user enter data in the text box,I put the total in the last text box(which set enabled = false).I sum the data entry in the text boxes through some method and call it in the event text changed . But every time i enter a number in the text box and then click Tab in the keyboard or use the mouse cursor to move to the next box i lose the focus , and i have to put the mouse cursor again in the intended textbox.

I try the following methods to fix my problem but in vain .

 foreach (GridViewRow r in gv_Evaluation.Rows)
            {
                ((RadTextBox)r.Cells[3].FindControl("txt_evaluateWeights")).Attributes.Add("blur", "calc()");
            }

in my page load , this doesn't work at all.

---

protected void txt_evaluateWeights_TextChanged(object sender, EventArgs e)
{
    calc();
    ((TextBox)sender).Focus();
}

This way return the focus to the previous textbox (i mean the one which i already have done) not the text box i wanna the focus in, to enter the data.

EDIT:

My calc method:

private void calc()
        {
            float sum = 0;
            for (int i = 0; i < 7; i++)
            {
                RadTextBox txt1 = (RadTextBox)gv_Evaluation.Rows[i].Cells[3].FindControl("txt_evaluateWeights");
                int weight;
                bool result = Int32.TryParse(txt1.Text, out weight);
                if (result)
                {
                    sum += weight;
                }
            }

            double percentage;
            percentage = Math.Round((sum / 100) * 100, 2);
            RadTextBox txt3 = (RadTextBox)gv_Evaluation.Rows[7].Cells[3].FindControl("txt_evaluateWeights");
            txt3.Text = percentage.ToString();//string.Format("{0:0.0%}", percentage.ToString());

        }

Answer 1

Doing it using server side PostBack is a horrendous way of doing this.

Use JavaScript instead. Here is a small example in jQuery

The GridView

<asp:GridView ID="DemoGrid" runat="server"
            AutoGenerateColumns="false"
            ShowFooter="true">
    <Columns>
        <asp:TemplateField HeaderText="index">
            <ItemTemplate><%# Container.DataItemIndex + 1 %></ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Item">
            <ItemTemplate>
                <asp:Label ID="DemoLabel" runat="server" Text='<%# Container.DataItem %>' />
            </ItemTemplate>
            <FooterTemplate>Total</FooterTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Amount">
            <ItemTemplate>
                <asp:TextBox ID="DemoText" runat="server" CssClass="quantity">
                </asp:TextBox>
            </ItemTemplate>
            <FooterTemplate>
                <asp:Label ID="TotalLabel" runat="server" CssClass="result"/>
            </FooterTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

The Code Behind

protected void Page_Load(object sender, EventArgs e){
    if (!IsPostBack)
    {
        string[] array = new string[] { "demo1", "demo2", "demo3", "demo4", "demo5" };
        DemoGrid.DataSource = array;
        DemoGrid.DataBind();
    }
}

The JavaScript (jQuery)

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $(".quantity").bind("blur", function () {
            var $quantity = $(this);
            var quantity = +$quantity.val(); //cast to number
            if (!isNaN(quantity)) {
                var $sum = $quantity.closest("table").find("tr:last .result");
                var sum = +$sum.html();
                $sum.html(sum + quantity);
            }
        });
    });
</script>

Hope this helps