RadListBox - Multi Select With Select All Option

This article will show you how to have an item which checks/unchecks all items. 

Select All  OR Un Select All  - sing Rad Combo / List Box Control

The aspx File

<script language="javascript" type="text/javascript">

    function OnClientItemChecked(sender, eventArgs) {

        var lstBoxControl;

        lstBoxControl = $find(sender.get_id());

        var items = lstBoxControl.get_items();

        if (eventArgs.get_item().get_index() == 0) {

            var firstIndex = eventArgs.get_item().get_checked();

            for (var i = 0; i < lstBoxControl.get_items().get_count(); i++) {

                items.getItem(i).set_checked(firstIndex);

            }

        }

        else {

            items.getItem(0).set_checked(false);

        }

    }

</script>

<telerik:RadListBox AppendDataBoundItems="true" TabIndex="1" Width="200px" CheckBoxes="true" ID="lstClassificationTypes" DataSourceID="dataClassificationTypes" runat="server" DataTextField="SelectionName" DataValueField="SelectionId" OnClientItemChecked="OnClientItemChecked">

<Items>

<telerik:RadListBoxItem Text="Select / UnSelect All" Value=0 BackColor=Gray Font-Bold="true" ForeColor=White />

</Items>

</telerik:RadListBox> 

The aspx.cs File

Find Selected Item

protected void btnGenerate_Click(object sender, EventArgs e)

    {

        StringBuilder sb = new StringBuilder();

        IList<RadListBoxItem> collection = ((RadListBox)fview.FindControl("lstClassificationTypes")).CheckedItems;

        foreach (RadListBoxItem item in collection)

        {

            // Your Code Here >> item.Value

        }

    }

If you need additional assistance, do not hesitate to contact me.@ tkjagadheesh@gmail.com

Regards,

JAG

Tags: RadListBox, C#, CheckBox, Java Script, Multiple Items, ASP.NET, AJAX, Rad Controls check all, Un check all, Select all, Multi Select Combo, MultiSelect List Box