CheckedItems.Count Always Returns a Value of Zero (0)

Question

I have Use telerik:radcombobox with mutiple select value.I have bind data LoadOndemand.All Work Fine but when i click on submit button then CheckedItems.Count=0.

Thank you,

Dhiren Patel

Answer 1

I believe you are using EnableLoadOnDemand property of the RadComboBox. RadComboBox items are not accessible on the server-side when loading them on demand and therefore always return CheckedItems as well as SelectedItems count as zero and this is a known issue. This is because RadComboBox items loaded on demand using the ItemsRequested event handler or WebService do not exist on the server and cannot be accessed using the server-side FindItemByText / Value methods. SelectedItem and SelectedIndex properties are always Null / Nothing. This is needed for speed (otherwise the combobox will not be that responsive upon each keypress if state information and ViewState were persisted).

Please have a look at the following code without using load on demand which works fine at my end.

<telerik:RadComboBox runat="server" ID="RadComboBox1" CheckBoxes="true">
</telerik:RadComboBox>
<br />
<br />
<telerik:RadButton ID="RadButton1" runat="server" Text="Get Count" OnClick="RadButton1_Click">
</telerik:RadButton>

Code Behind:

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
    populateRadCombobox("select ContactName from Customers");
}
}
protected void populateRadCombobox(string query)
{
String ConnString =
ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString;
SqlConnection conn = new SqlConnection(ConnString);
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = new SqlCommand(query, conn);

DataTable myDataTable = new DataTable();

conn.Open();
try
{
    adapter.Fill(myDataTable);
    RadComboBox1.DataTextField = "ContactName";
    RadComboBox1.DataSource = myDataTable;
    RadComboBox1.DataBind();
}
finally
{
    conn.Close();
}
}
protected void RadButton1_Click(object sender, EventArgs e)
{
if (RadComboBox1.CheckedItems.Count > 0)
{
    //business logic goes here
}
else
{

}

Reference: http://www.telerik.com/forums/checkeditems-count-always-returns-a-value-of-zero-0

http://www.telerik.com/forums/radcombobox-losing-client-selections-on-postback