private void SetDataSources()
{
var allProducts = ProductOperations.GetAll()?.ItemList ?? new List <ProductDto>();
var branchProducts = ddlBranches.SelectedValue == "0" ? new List <ProductDto>() : ProductOperations.GetAllByStoreId(int.Parse(ddlBranches.SelectedValue));
RadListBoxSource.DataSource = branchProducts.Count > 0 ? allProducts.Where(p => !branchProducts.Contains(p)) : allProducts;
RadListBoxSource.DataBind();
RadListBoxDestination.DataSource = branchProducts;
RadListBoxDestination.DataBind();
}