Filtering ListBox.ItemsSource with CheckBoxes

Question

I'm pretty new to programming for Windows Phone and I'm having trouble editing data in ListBox.
I'm loading data from my XML file into a list, and displaying them in ListBox.
Each entry in my XML has a type attached to it. I want to make it so I can remove/add entries with certain types, by checking/unchecking certain CheckBoxes.

I found something like this:
How to remove all ListBox items?

But it doesn't exactly suit my needs since I want only to delete part of ListBox items, and then possibly get it back by simply checking the checkbox again.
Also I don't want to add every entry manually since I already bound listbox with a list containing my XML entries.

I upload my XML like so:

Activity.cs:

namespace ReadXMLfromFile
{
   public class Activity
   {
      public string Type { get; private set; }
      public string Description { get; private set; }

      public Activity(string type, string description)
      {
           Type = type;
           Description = description;
      }

      public static List<Activity> LoadActivities(XDocument doc)
      {
        return doc .Root
                   .Elements("Activity")
                   .Select(el => new Activity((string)el.Attribute("Type"),
                                            el.Value))
                   .ToList();
      }

      public static List<Activity> LoadActivities()
      {
        using (var store = IsolatedStorageFile.GetUserStoreForApplication())
        {
            if (store.FileExists("Activities.xml"))
            {
                 using (var stream = store.OpenFile("Activities.xml",
                                                    FileMode.Open))
                 {
                     return LoadActivities(XDocument.Load(stream));
                 }
            }
        }
        // No user file... load the default activities
        return LoadActivities(XDocument.Load("Assets/Activities.xml"));

      }
   }
}

Here is my code for my page:

namespace ActivityManager
{
    public partial class PivotPage1 : PhoneApplicationPage
    {
        private List<Activity> activities;

        public void ActivityDisplay()
        {
            activities = Activity.LoadActivities();
            listBox1.ItemsSource = activities;
        }

        public PivotPage1()
        {
            InitializeComponent();
            ActivityDisplay();
        }

        private void CookingCheck_Checked(object sender, RoutedEventArgs e)
        {
        }

        private void ArtCheck_Checked(object sender, RoutedEventArgs e)
        {
        }

        private void LanguageCheck_Checked(object sender, RoutedEventArgs e)
        {
        }

        private void ScienceCheck_Checked(object sender, RoutedEventArgs e)
        {
        }

        private void SportCheck_Checked(object sender, RoutedEventArgs e)
        {
        }

And xaml for ListBox:

<ListBox Height="347" HorizontalAlignment="Left" Margin="27,243,0,0" 
         Name="listBox1" VerticalAlignment="Top" Width="410" 
         SelectionChanged="listBox1_SelectionChanged" AllowDrop="False" 
         ItemsSource="{Binding activities}">
     <ListBox.ItemTemplate>
         <DataTemplate>
              <StackPanel Margin="10">
                   <TextBlock Text="{Binding Activity}"/>
              </StackPanel>
         </DataTemplate>
     </ListBox.ItemTemplate>
 </ListBox>

Also here is my XML file

<?xml version="1.0" encoding="utf-8" ?>
<Activities>
    <Activity Type="Cooking">
      Cook some Mexican food
    </Activity>
    <Activity Type="Art">
      Draw a picture
    </Activity>
    <Activity Type="Language">
      Learn 5 words in Polish you didn't know yet
    </Activity>
    <Activity Type="Science">
      Write a simple program in C
    </Activity>
    <Activity Type="Sport">
      Go to the gym
    </Activity>
  </Activities>

Can you help me? I'm pretty stuck and probably missing something obvious. Thank you in advance.

Answer 1

You should do this way:
Create a list of filters.
Update the list of filters when checking/unchecking the checkboxes, and at each filter change update the List

private List<Activity> activities;

public void ActivityDisplay()
{
    activities = Activity.LoadActivities();
    FilterActivities();
}

public ObservableCollection<string> ActivityFilter = new ObservableCollection<string>();

private void FilterActivities()
{
    listbox1.ItemsSource = null; //sometimes it makes the difference;
    listBox1.ItemsSource = activities.Where(activity => ActivityFilter.Any(filter => filter == activity.Type) || ActivityFilter.Count == 0);

}

public PivotPage1()
{
    InitializeComponent();
    ActivityFilter.CollectionChanged += ActivityFilter_CollectionChanged;
    ActivityDisplay();
}

void ActivityFilter_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
    FilterActivities();
}

private void CookingCheck_Checked(object sender, RoutedEventArgs e)
{
    ActivityFilter.Add("Cooking");
}

private void CookingCheck_Unchecked(object sender, RoutedEventArgs e)
{
    ActivityFilter.Remove("Cooking");
}

//Repeat the procedure for each checkbox

I found an issue in your ItemTemplate use this one

 <ListBox.ItemTemplate>
     <DataTemplate>
          <StackPanel Margin="10">
               <TextBlock Text="{Binding Description}"/>
          </StackPanel>
     </DataTemplate>
 </ListBox.ItemTemplate>