Gridview中的必填字段验证器取决于条件c＃

Question

I have a required field validator in a Gridview. I want fire the validater only if the ddlPartsStatus is "Ordered". I just can't get it to work.

At the moment required field validator fires for all the textboxes.

my code

<asp:GridView ID="gvPartsToOrderDetail" CssClass="gvPartsToOrderDetail" runat="server" AutoGenerateColumns="false" OnRowDataBound="gvPartsToOrderDetail_RowDataBound">
    <Columns>
        <asp:TemplateField HeaderText="Ticket Number">
            <ItemTemplate>
                <asp:TextBox ID="txtTicketNo" Text='<%# Eval("TicketNo") %>' runat="server"></asp:TextBox>
                <asp:RequiredFieldValidator ID="rfvTxtTicketNo" runat="server" ForeColor="Red" Font-Bold="true" Font-Size="Medium" ErrorMessage="*" ControlToValidate="txtTicketNo" ValidationGroup="Submit"></asp:RequiredFieldValidator>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Parts Status">
            <ItemTemplate>
                <asp:DropDownList ID="ddlPartStatus" runat="server" AutoPostBack="true">
                    <asp:ListItem Value="0" Text="-Select-"></asp:ListItem>
                    <asp:ListItem Value="1" Text="Ordered"></asp:ListItem>
                </asp:DropDownList>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

<asp:Button ID="btnSubmit" CssClass="btnSubmit" runat="server" Text="Submit" ValidationGroup="Submit" OnClick="btnSubmit_Click" />

Any help is greatly appreciated. Thanks

Answer 1

For this you need a CustomValidator . Then the ClientValidationFunction should evaluate both the TextBox and the DropDownList.

<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="*" 
    ValidationGroup="Submit" ControlToValidate="txtTicketNo" 
    ClientValidationFunction="checkValuesInRow" ValidateEmptyText="true"></asp:CustomValidator>

<script type="text/javascript">
    function checkValuesInRow(sender, element) {
        var isValid = false;
        var ddlValue = $("#" + sender.controltovalidate).closest('tr').find('select').val();
        if (element.Value === "" && ddlValue === "0") {
            isValid = true;
        }
        element.IsValid = isValid;
    }
</script>

Answer 2

NOTE: Further reading is intended to be informative and not practical given all the clicking that must happen. But it shows how things can be done, not necessarily how the should be done and is only here due to the OP's Request for more info...so, here we go

Given this GridView <ItemTemplate> :

    <asp:TextBox ID="tbxTicketNo" runat="server" Text='<%# Bind("TicketNo") %>'></asp:TextBox>
    <asp:RequiredFieldValidator ID="rfvTxtTicketNo" runat="server" 
        ErrorMessage="RequiredFieldValidator" Text="*"
        ControlToValidate="tbxTicketNo"
        InitialValue="0"
        ValidationGroup="vgSubmit">
    </asp:RequiredFieldValidator>

Renders a table with x number of validators based on your row count. You can use your browser's Developers Tools to inspect gvPartsToOrderDetail where you will find something similar to this, note the data-val-validationgroup attributes on all rows:

    <span 
      data-val-controltovalidate="ContentPlaceHolder1_gvPartsToOrderDetail_tbxTicketNo_0" 
      data-val-errormessage="RequiredFieldValidator" 
      data-val-validationgroup="vgSubmit"
      id="ContentPlaceHolder1_gvPartsToOrderDetail_rfvTxtTicketNo_0" 
      data-val="true" 
      data-val-evaluationfunction="RequiredFieldValidatorEvaluateIsValid" 
      data-val-initialvalue="0" style="visibility:hidden;">*</span>

Do you see that data-val-validationgroup="vgSubmit" is not unique? So when you click btnSubmit with its ValidationGroup set to "vgSubmit", they all get triggered.

Now given @VDWWD's answer you may well prefer to keep it this way. And that's perfectly fine and legal and likely more in line with your needs.

But to address the non-uniqueness of the Validation Group you can do this in the markup instead:

    <asp:RequiredFieldValidator ID="rfvTxtTicketNo" runat="server" 
        ...
        ValidationGroup='<%# string.Format("Submit_{0}", Container.DataItemIndex) %>'>
    </asp:RequiredFieldValidator>

which will then render:

<span ... data-val-validationgroup="Submit_0" ... </span>
<span ... data-val-validationgroup="Submit_1" ... </span>
<span ... data-val-validationgroup="Submit_2" ... </span>

But now you have design problem. To isolate the validation group in the gridview and to tie it to your submit button you need to select a row, which means introducing a Select command button. More clicks, not good, but it can be done. But this introduces a couple of more issues:

1. How do you tell the Submit button which validation group to validate?
2. Also the Submit button has a nasty habit of Posting back regardless of validation.

Both can be fixed like this:

    <asp:Button ID="btnSubmit" runat="server" Text="Button" 
        OnClientClick="return Page_ClientValidate('vgSubmit_1')" />

which is generated programmatically in btnSubmit_PreRender as follows:

    protected void btnSubmit_PreRender( object sender, EventArgs e )
    {
        btnSubmit.OnClientClick = string.Format( "return Page_ClientValidate('vgSubmit_{0}')", gvPartsToOrderDetail.SelectedIndex );
    }

What follows is the Code behind and the page markup for review:

To sum up, this solution, if you can call it that:

1. Unique validation group names PER ROW
2. Requires the addition of a selected row
3. Rendering the Submit button to prevent postbacks and isolate the appropriate validation group

I can only hope this was at least informative and maybe gave you some ideas about the versatility of Server controls.

Happy Programming...

Code behind:

namespace WebApplication3
{
    public partial class _Default : Page
    {
        protected void Page_Load( object sender, EventArgs e )
        {
            if ( !Page.IsPostBack )
            {
                List<Parts> ListOfParts = new List<Parts>( new Parts[ ] {
                            new Parts(0, 0),
                            new Parts(0, 0),            
                            new Parts(0, 0) } );

                gvPartsToOrderDetail.DataSource = ListOfParts;
                gvPartsToOrderDetail.DataBind();
            }
        }

        protected void Button1_PreRender( object sender, EventArgs e )
        {
            Button1.OnClientClick = string.Format( "return Page_ClientValidate('vgSubmit_{0}')", gvPartsToOrderDetail.SelectedIndex );
        }
    }

    //------------------------------------------------------------
    // Dummy data class
    //
    public class Parts {
        public Parts( int ticketNo, int status ) {
            TicketNo = ticketNo;
            Status = status;
        }

        public int TicketNo { get; set; }
        public int Status { get; set; }
    }
}

And the Markup:

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site1.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication3._Default" %>

<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="ContentPlaceHolder1">
    <asp:GridView ID="gvPartsToOrderDetail" runat="server" AutoGenerateColumns="False" 
        AutoGenerateSelectButton="True" ClientIDMode="Predictable">
        <Columns>
            <asp:TemplateField HeaderText="Ticket">
                <ItemTemplate>
                    <asp:TextBox ID="tbxTicketNo" runat="server" Text='<%# Bind("TicketNo") %>'></asp:TextBox>
                    <asp:RequiredFieldValidator ID="rfvTxtTicketNo" runat="server" 
                        ErrorMessage="RequiredFieldValidator" Text="*"
                        ControlToValidate="tbxTicketNo"
                        ValidationGroup='<%# string.Format("vgSubmit_{0}", Container.DataItemIndex) %>'>
                    </asp:RequiredFieldValidator>

                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Parts Status">
                <ItemTemplate>
                    <asp:DropDownList ID="ddlPartStatus" runat="server">
                        <asp:ListItem Text="[ Select ]" Value="0"></asp:ListItem>
                        <asp:ListItem Text="Ordered" Value="1"></asp:ListItem>
                    </asp:DropDownList>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>

    </asp:GridView>

    <asp:Button ID="btnSubmit" runat="server" Text="Button" 
        OnClientClick='See code in PreRender' 
        OnPreRender="btnSubmit_PreRender" />

</asp:Content>