Reference error in an expandable listview - xaml

Question

I am trying to create an expandable listview in forms and I am receiving an error "The type or namespace name 'Items' could not be found (are you missing a using directive or an assembly reference?)" I was trying to have the buttons hide or show with a boolean value upon touch.
using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace ExpandableListViewTest
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class ListViewType : ContentPage
{
public ObservableCollection<string> Items { get; set; }
public bool IsVisible { get; set; }
public ListViewType()
{
InitializeComponent();
IsVisible = false;
Items = new ObservableCollection<string>
{
new Items
{
Title = "Sad"
},
new Items
{
Title = "Angry"
},
new Items
{
Title = "Fearful"
}
};
}
public void HideOrShowItem(Items item)
{
item.IsVisible = true;
UpdateItems(item);
}
private void UpdateProducts(Items item)
{
var index = Items.IndexOf(item);
Items.Remove(item);
Items.Instert(index, item);
}
}
}

Answer 1

Your ObservableCollection Items has the type parameter string, but you are trying to create objects of type Items, which is not possible for two reasons
First of all (and this is what the compiler complains about) there is no type Items, hence you can't create instances of this type
Second, if the ObservableCollection has the type parameter string you can't add any items but strings.
You could either add strings to the collection
Items = new ObservableCollection<string>
{
"Sad",
"Angry",
"Fearful"
};
or you create the type Item (renamed it)
class Item
{
Title { get; set; }
}
and then create instances of that type:
Items = new ObservableCollection<Item>
{
new Item
{
Title = "Sad"
},
new Item
{
Title = "Angry"
},
new Item
{
Title = "Fearful"
}
};
Of course you have to change the type of Items to ObservableCollection<Item>, for the reason stated above (can't add objects of type Item to an ObservableCollection<string>).