Adding CheckBoxes to RadMenu Dynamic Items

[Holly]

Hi I have a RadMenu that I am populating dynamically through the code behind.  I need to add checkboxes to each child item that allows the user to make a selection or multiple selections in the menu.  Is it possible to do this?  Someone had suggested to me that I try and nest a RadComboBox inside of the RadMenu, but I'm having no luck with that.  I will paste my code below if it will help.

 <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                    <ContentTemplate>
                        <telerik:RadMenu ID="handsetMenu" runat="server">   
                        <Items>    
                                                
                        </Items>                                           
                    </telerik:RadMenu>
                    </ContentTemplate>
                </asp:UpdatePanel> 

 

Code Behind:

 

protected void createFilter(int categoryid)
    {
        List<int> productIds = new List<int>();
        DataRow[] productRow = CategoriesProductsData.Tables["Products"].Select("Category_ID = " + 573);

        productIds = productRow.Select(p => int.Parse(p["Product_ID"].ToString())).ToList();

        ITCProductService pService = new TCProductServiceClient();
        var productTuples = (pService.GetProductsAttributes(productIds));

        List<Tuple<int, CustomAttribute>> customAttributes = new List<Tuple<int, CustomAttribute>>();
        foreach (var productTuple in productTuples)
        {
            foreach (var attributeTuple in productTuple.m_Item2)
            {
                var customAttribute = new Tuple<int, CustomAttribute>(productTuple.m_Item1, new CustomAttribute(attributeTuple));
                customAttributes.Add(customAttribute);
            }

        }

        List<CustomAttributeCategory> categories = new List<CustomAttributeCategory>();

        var categoryList = customAttributes.Select(a => a.Item2).Select(a => a.Attribute.Category).GroupBy(a => a.AttributeCategoryId);

        var CatProdList = new List<CustomAttributeCategory>();

        foreach (var category in categoryList)
        {
            var CatProd = new CustomAttributeCategory();

            var prodIDList = from product in customAttributes
                             where product.Item2.Attribute.CategoryId == category.Key
                             select Tuple.Create(product.Item1, product.Item2);

            CatProd.Category = customAttributes.Select(a => a.Item2.Attribute.Category).Where(a => a.AttributeCategoryId == category.Key).FirstOrDefault();
            CatProd.ProdAttributesTuple = new List<Tuple<int, CustomAttribute>>();
            CatProd.ProdAttributesTuple = prodIDList.ToList();

            CatProdList.Add(CatProd);
        }

        foreach (var cat in CatProdList)
        {
            var itemCategory = new RadMenuItem(cat.Category.Name);
            
            handsetMenu.Items.Add(itemCategory);
            

            var option = cat.ProdAttributesTuple.GroupBy(a => a.Item2.Attribute.Value).ToList();
            foreach (var attr in option)
            {
                itemCategory.Items.Add(new RadMenuItem(attr.Key));              
                

            }
        }

    }


    protected void handsetMenu_ItemDataBound(object sender, RadMenuEventArgs e)
    {
        DataRowView row = (DataRowView)e.Item.DataItem;

    }


    public class CustomAttributeCategory
    {
        public AttributeCategoryModel Category { get; set; }
        public List<Tuple<int, CustomAttribute>> ProdAttributesTuple { get; set; }
    }

    public class CustomAttribute
    {
        public AttributeModel Attribute { get; set; }

        public List<int> ProductIds { get; set; }

        public CustomAttribute(AttributeModel attribute)
        {
            Attribute = attribute;
            ProductIds = new List<int>();
        }
    }​

[Holly]

So I think I'm almost there.  I realized that I needed to create a contenttemplate programatically and add the checkbox in the template.  But when I try to use it in my menu depending on where i put it, it replaces either my Parent or Child items with checkboxes.  How can I have both checkboxes and a Child Item with it?

Here's code.

class CustomContentTemplate : ITemplate
   {
       public void InstantiateIn(Control container)
       {
           CheckBox cb = new CheckBox();
           container.Controls.Add(cb);
       }

         private void cb_DataBinding(object sender, EventArgs e)
       {
           CheckBox target = (CheckBox)sender;
           RadMenuItem item = (RadMenuItem)target.BindingContainer;
           target.Text = item.Value;
       }
   }

  

 foreach (var cat in CatProdList)
        {
            var itemCategory = new RadMenuItem(cat.Category.Name);
                        
            handsetMenu.Items.Add(itemCategory);

                       

            var option = cat.ProdAttributesTuple.GroupBy(a => a.Item2.Attribute.Value).ToList();
            foreach (var attr in option)
            {               
                itemCategory.Items.Add(new RadMenuItem(attr.Key));

                foreach (RadMenuItem item in handsetMenu.Items)
                {
                    CustomContentTemplate template = new CustomContentTemplate();
                    template.InstantiateIn(item);
                    item.DataBind();
                }               
                
            }
                 ​

[Aneliya Petkova]

Hi Holly,

Please check the following help article providing more information on how to add Text on the CheckBoxes inside RadMenu's ItemTemplate:

• http://docs.telerik.com/devtools/aspnet-ajax/controls/menu/templates/databinding-expressions

You may also find useful "Accessing controls inside templates" help article:

• http://docs.telerik.com/devtools/aspnet-ajax/controls/menu/templates/accessing-controls-inside-templates

Hope this will be helpful.

Regards,
Aneliya Petkova
Telerik

[Holly]

Aneliya 

 These don't resolve my issue.  I'm actually creating my template that contains my CheckBox in the code behind.  I can't create it in the HTML, as the menu is built dynamically.  I have the following code where I create my template, and then in a button click event I try to access the checkbox, but I get back the error, An exception of type 'System.NullReferenceException' occurred in App_Web_umdevm1i.dll but was not handled in user code.  I don't think I'm accessing the control inside the template correctly.  Do you have any other advice?  Thanks.

Additional information: Object reference not set to an instance of an object.

 class CustomContentTemplate : ITemplate
    {
        public void InstantiateIn(Control container)
        {
            CheckBox cb = new CheckBox();

            cb.Text = "Text";

            cb.DataBinding += new EventHandler(cb_DataBinding);
            container.Controls.Add(cb);            
            
        }

        private void cb_DataBinding(object sender, EventArgs e)
        {
            CheckBox target = (CheckBox)sender;
            RadMenuItem item = (RadMenuItem)target.BindingContainer;
            target.Text = item.Text;                    
        }
    }

 

 

protected void btnSubmit_Click(object sender, EventArgs e)
    {
        RadMenuItem item = handsetMenu.Items[0];
        CheckBox CheckItem = item.FindControl("cb") as CheckBox;
        CheckItem.Checked = false;  
           
    }

 

 

 

[Aneliya Petkova]

Hi Holly,

Please note that RadMenuItem item = handsetMenu.Items[0]; will return first root node in your RadMenu. If this root node doesn't have CheckBox control, a null reference exception will be thrown. Also note that .FindControl method searches for a server control with the specified ID parameter.

I tried the provided code and everything is working fine at my side. In order to help you, I will need a sample runnable project where I can inspect your RadMenu with templates implementation and see why you get this error.

Regards,
Aneliya Petkova
Telerik