CODEWITHSUNDEEP
c#asp.netcheckboxlist
user1858332
user1858332

Reputation: 2075

Check if at least one checkboxlist is selected

I have checkboxlist and I would like to check if at least one checkbox is checked. If none is checked then I want to show alert message that says please select at least one item. I want to do this in code behind if possible. I have started but don't know if it is right or wrong but not able to finish it. 

 public void alert()
    {
        foreach (ListItem listItem in cblCustomerList.Items)
        {
            if (!listItem.Selected)
            {
            }
        }
    }

here is the checkboxlist in aspx:

 <asp:CheckBoxList ID="cblCustomerList" runat="server" DataSourceID="SqlDataSource1" CssClass="CheckBoxList"
            DataTextField="GroupName" DataValueField="GroupName" 
                onclick="readCheckBoxList()" >               
            </asp:CheckBoxList>

here is the button:

 <asp:Button ID="Button1" runat="server" CausesValidation="True" 
                            CommandName="Insert" Text="Insert" OnClientClick="return Validate_Checkbox()" />

Thanks for your help.

Upvotes: 10

Views: 33624

Answers (9)

John M
John M

Reputation: 14668

Using built-in 'CheckedItems':

 dim x1 As Integer = clbMoveTo.CheckedItems.Count
 If x1 <= 0 Then
     MessageBox.Show("Select Move To.","Verify")
     return
  End If

Upvotes: 0

user1193035
user1193035

Reputation:

Edit:

Here is one sample code. its working to me

Must add this script file :<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>

 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript">
        function Validate_Checkbox() {
            var chks = $("#<%= cblCustomerList.ClientID %> input:checkbox");          

            var hasChecked = false;
            for (var i = 0; i < chks.length; i++) {
                if (chks[i].checked) {
                    hasChecked = true;
                    break;
                }
            }
            if (hasChecked == false) {
                alert("Please select at least one checkbox..!");

                return false;
            }

            return true;
        }     
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:CheckBoxList ID="cblCustomerList" runat="server" CssClass="CheckBoxList">
            <asp:ListItem Value="0">xx</asp:ListItem>
            <asp:ListItem Value="1">yy</asp:ListItem>
        </asp:CheckBoxList>
        <asp:Button ID="xx" runat="server" OnClientClick="javascript:Validate_Checkbox();return true;" />
    </div>
    </form>
</body>
</html>

and you change 

<asp:CheckBoxList ID="cblCustomerList" runat="server" DataSourceID="SqlDataSource1" CssClass="CheckBoxList" DataTextField="GroupName" DataValueField="GroupName">             
            </asp:CheckBoxList>

control instead of my sample code . and call the javascript function in the button control.look my sample code.

Chears!!!

Edit

please add this script file 

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>

Instead of <script src="scripts/jquery-1.8.3.min.js" type="text/javascript"></script>

Upvotes: 8

codeandcloud
codeandcloud

Reputation: 55200

jQuery solution.

if (!$(".CheckBoxList").find("input:checked").length) {
    alert("Houston, we've had a problem!");
}

Upvotes: 1

Prasad Kanaparthi
Prasad Kanaparthi

Reputation: 6563

        if(! cblCustomerList.Items.Cast<ListItem>().AsParallel().Any(i => i.Selected))
        {
           ShowAlert("Please select at least one option");
        }

Upvotes: 1

SamuraiJack
SamuraiJack

Reputation: 5539

The simplest way i can think of....

public void alert()
        {
            int i=0;
            foreach (ListItem listItem in cblCustomerList.Items)
            {
                if (listItem.Selected)
                {
                    i++;
                }
            }
            if(i !=0)
            {
                Response.Write("Please check at least one option");
            }
        }
    }

Upvotes: 0

Greg B
Greg B

Reputation: 426

You would just use cblCustomerList.SelectedItem == null, SelectedItem will return the lowest ordinal item in the list of checked items, so if nothing is returned, nothing is checked.

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.checkboxlist.aspx

Upvotes: 3

Soner G&#246;n&#252;l
Soner G&#246;n&#252;l

Reputation: 98740

Try this;

boolean b = cblCustomerList.Items.Cast<ListItem>().Any(i => i.Selected)

if b is true, at least one is selected in your checkboxlist.

Don't forget to use System.Linq namespace.

Upvotes: 5

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236188

if(cblCustomerList.Items.Cast<ListItem>().Any(item => item.Selected))
{
   // at least one selected
}

Upvotes: 13

sll
sll

Reputation: 62484

// using System.Linq;

// Considering that items are of ListItem type, otherwise use Cast<ListItem>()
if (!cblCustomerList.Items.Any(i => i.Selected))
{
    // TODO: Warn an user
}

Upvotes: 4

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