Hi,

How can i validate multiple check box or checkboxlist using required field validator .

i want to check if any one check box is checked or not.

Thanks,

Saurabh

Although RequiredFieldValidators can be applied on RadioButtonLists and DropDownLists, you can't apply them on CheckBox or CheckBoxLists. Because its valid to have a checkbox not checked at all.

So in order to put this kind of logic, you'll have to go for CustomValidators. Please note that we'll keep the ControlToValidate property of the CustomValidator to empty. Because a validator can't be applied on a CheckBoxList.

Lets suppose we've a checkbox list of three checkboxes and we want to do postback only if any one of three is checked.

    <asp:CheckBoxList ID="chkList1" runat="server">
    <asp:ListItem>Red</asp:ListItem>
    <asp:ListItem>Green</asp:ListItem>
    <asp:ListItem>Blue</asp:ListItem>
    </asp:CheckBoxList>
    <asp:CustomValidator ID="CustomValidator1" runat="server" ClientValidationFunction="CheckBoxCheck" ErrorMessage="Please check at least one" ValidationGroup="VG"></asp:CustomValidator>
    <asp:Button ID="btn1" runat="server" Text="Submit" ValidationGroup="VG" />

And the javascript method which does the validation is

        function CheckBoxCheck(sender, args) {
            if (document.getElementById("chkList1_0").checked || document.getElementById("chkList1_1").checked || document.getElementById("chkList1_2").checked) {
                args.IsValid = true;
                return;
            }
            args.IsValid = false;
        }

Please refer to following thread for more details

http://forums.asp.net/t/1218279.aspx

Hope it helps

Thanks a lot...It not only soved my problem but i got idea how to solve some other issues also....

If it solved your problem then please mark it as answer.

All the best