如何验证将从数据库值生成的复选框列表

Question

There is no validation controle for checkboxlist in asp.net ,C#. Checkbox will be generated from the database values and that will place in the panel. But the problem is I can not validate the checkboxlist. Can someone tell me, how I can solve this problem.

Answer 1

Use a CustomValidator in your code to use ASP.NET to verify.

<asp:CheckBoxList ID="CheckBoxList1" runat="server"
    ClientID="MyCBL"
    DataSource="datasource"
    DataTextField="display"
    DataValueField="value">
</asp:CheckBoxList>

<asp:CustomValidator ID="CustomValidator1" runat="server"
    ErrorMessage="You must select a value."
    ClientValidationFunction="VerifyCheckBoxList">
</asp:CustomValidator>

Javascript

function VerifyCheckBoxList(sender, args) {
    var mycbl = document.getElementById('<%=MyCBL.ClientID%>').value;
    if (...) { // verify your checkbox list here
        args.IsValid = false; // pass false to cancel postback
    }
    else {
        // do your other things
    }
}

Take a look at the MSDN page at http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.customvalidator(v=vs.110).aspx