RadComboBox with checkboxes in Radgrid - select values from the table - telerik

Question

I have a RadComboBox with checkboxes in Radgrid. User is able to select multiple values and data is saved into database. The problem I am having is, how to display already selected values when pulling data from database.
<telerik:RadGrid RenderMode="Lightweight" AutoGenerateColumns="false" ID="grd_incontact_settings" BorderWidth="0" Font-Size="Smaller" Width="100%" ShowFooter="True" AllowPaging="True" runat="server" PageSize="250" PagerStyle-AlwaysVisible="true"
OnNeedDataSource="grd_incontact_settings_NeedDataSource" AllowAutomaticInserts="True" OnInsertCommand="grd_incontact_settings_InsertCommand">
<GroupingSettings CaseSensitive="false"></GroupingSettings>
<MasterTableView AutoGenerateColumns="false" CommandItemDisplay="TopAndBottom" DataKeyNames="Id" EditMode="InPlace" ShowHeader="true">
<Columns>
<telerik:GridBoundColumn DataField="Id" UniqueName = "Id" AllowFiltering="false" Display ="false">
</telerik:GridBoundColumn>
<telerik:GridTemplateColumn HeaderText="Days" HeaderStyle-Width="150px" ItemStyle-Width="150px" UniqueName="ScheduleDays">
<ItemTemplate>
<%# Eval("ScheduleDays") %>
</ItemTemplate>
<EditItemTemplate>
<telerik:RadComboBox RenderMode="Lightweight" runat="server" ID="ddl_ScheduleDays" CheckedItemsTexts="DisplayAllInInput" CheckBoxes="true" SelectedValue='<%#Bind("ScheduleDays") %>' >
<Items>
<telerik:RadComboBoxItem Text="None" Value= 0 runat="server" />
<telerik:RadComboBoxItem Text="Monday" Value= 1 runat="server" />
<telerik:RadComboBoxItem Text="Tuesday" Value= 2 runat="server" />
<telerik:RadComboBoxItem Text="Wednesday" Value= 4 runat="server" />
<telerik:RadComboBoxItem Text="Thursday" Value= 8 runat="server" />
<telerik:RadComboBoxItem Text="Friday" Value= 16 runat="server" />
<telerik:RadComboBoxItem Text="Saturday" Value= 32 runat="server" />
<telerik:RadComboBoxItem Text="Sunday" Value= 64 runat="server" />
</Items>
</telerik:RadComboBox>
</EditItemTemplate>
</telerik:GridTemplateColumn>
</Columns>
</MasterTableView>
</telerik:RadGrid>
Code Behind:
protected void grd_incontact_settings_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
{
List<SP_InContactSettings_Get_Result> lst_incontact_settings = new List<SP_InContactSettings_Get_Result>();
using (var db = new data.tarpasql())
{
lst_incontact_settings = db.SP_InContactSettings_Get().ToList();
}
grd_incontact_settings.DataSource = lst_incontact_settings;
}
public partial class SP_InContactSettings_Get_Result
{
public int Id { get; set; }
public List<int> ScheduleDays { get; set; }
}
This is what I am getting: