how to give required field validator to textbox in gridview?

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" Height="146px"
            Width="308px">
            <Columns>            
                    <asp:TemplateField HeaderText="Original Price" ControlStyle-Width="100px">
                    <ItemTemplate>
                        <asp:TextBox ID="txtOriginalPrice" runat="server"></asp:TextBox>
                         <asp:RequiredFieldValidator ID="rfv" runat="server" ControlToValidate="txtOriginalPrice" 
                         ValidationGroup="GridView1" Display="Static" ErrorMessage="" Text="*"></asp:RequiredFieldValidator> 

                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

I am using above code but its not working though I开发者_运维技巧 have put requirefield validator it does not show me the '*'

Yes, your requiredfieldvalidator is certainly there, and it knows which control to validate.What is missing is "when to validate that control".And to answer this question you need to add your textbox the same ValidationGroup with your requiredfieldvalidator and also the control(this can be a button for example) causes to do a validation.So your code will be like

<%--<asp:Button ID="Button1" runat="server" ValidationGroup="GridView1" Text="Benjamin"...Somewhere in your code--%>    
    <asp:TextBox ID="txtOriginalPrice" runat="server" ValidationGroup="GridView1"></asp:TextBox> 

So don't forget these question

1. What to validate?(a textbox)
2. When to validate?(after a button click)
3. After what action try to validate?(a button click)
4. With what to validate?(a requiredfieldvalidator)

All of these controls must have the same ValidationGroup.

In case you need the validation to be performed then check for something like this

<asp:Button ID="btnAdd" runat='server' ValidationGroup='GridView1' CausesValidation='true'.....

So now when you click the add button it will validate for those controls falling under the validation group you mentioned else the default value is "" hence you won't find any validation triggered.

Add ValidationGroup to TextBox (txtOriginalPrice), Button and other controls.