insert items into checkboxlist without duplications

Question

Hi Guys,

I need your help please, thanks in advance,

I have 2 tabs each one of them contains unbound checklistbox, example Checklistbox name Chapp contains all user application and Chshared have all shared drive names. I have another list I created that has similar or different items  I want to add items of this list to each appropriate checkboxlist without creating any duplicates. example

Chapp list has

adobe

Office

Chshared has 

c: @drive

d: @drive

the new list

Adobe

c:@drive.

k:@drive

public void loadapp()
        {

            IEnumerable<ConcreteDataObject> productCategories = concreteDataApi.FindAllByType("ProductCategory")
                  .Where(c => c.Name == TextBoxDepartment.Text.ToString());

            using (ProductManagementDataContext ctx = DataContextFactory.Create<ProductManagementDataContext>())

                foreach (ConcreteDataObject productCategory in productCategories)
                {
                    IQueryable<Product> q = from p in ctx.Products
                                            where p.CategoryId == productCategory.Id
                                            select p;


                    foreach (var productItems in q)
                    {

                        if (!chapp.Items.Cast<ListItem>().Where(r => r.Selected).Any(m => m.Text == productItems.Name && !productItems.Name.Contains("@")))

                            // 

                            chapp.Items.Add(productItems.Name);
                        else if ((chShared.Items.Cast<ListItem>().Where(r => r.Selected).Any(m => m.Text == productItems.Name && !productItems.Name.Contains("@"))))
                        {
                            chShared.Items.Add(productItems.Name);
                        }
                           
                        userEMAIL.Add(
                            new Dictionary<string, string>(){
                            {productItems .Name, productItems .Manufactory} });

                         
                    }
                }    
        }