binding image control to listbox selected item

Question

I have a listbox,inside that item template,and inside that data template(as usual). My aim is- in listbox selection changed event, I want to bind listbox selected item to a image control-and my code is--

ListBox lb = (ListBox)sender;

ListBoxItem item = (ListBoxItem)lb.SelectedItem;

Image im = (Image)item.Content;
Image1.Source = new BitmapImage(((BitmapImage)im.Source).UriSource);

and my ListBox.ItemTemplate looks like this:

<ListBox Name="imageList" Height="556" Width="130" HorizontalAlignment="Left" Style="{StaticResource ListBoxStyle1}" SelectionChanged="imageList_SelectionChanged" >
   <ListBox.ItemTemplate>
      <DataTemplate>
         <Image Source="{Binding Imgs}" Width="100" Height="100"/>
      </DataTemplate>
   </ListBox.ItemTemplate>
</ListBox>

But it is showing exception. Image1 is my image control and I don't want to bind image source in xaml. I have some certain requirements.

Answer 1

You have excepion because when you bind ListBox , and I assume you do, or any ItemsControl for that matter, properties like Items , SelectedItem and SelectedItems will be of a type of bound list item and not ListBoxItem , which is just a container. If you need ListBoxItem refer to it like that:

var listBox = sender as ListBox;
var lbi = (ListBoxItem)listBox
                         .ItemContainerGenerator
                         .ContainerFromItem(listBox.SelectedItem)

but if your Image is part of DataTemplate it won't be as easy as getting Content . Again it will be of a type of bound item, basically point to the same as SelectedItem . Maybe you can use that as otherwise you will need to refer to VisualTreeHelper as by default there will be other controls in visual tree between ListBoxItem and your DataTemplate Image . I undrestand you don't want to bind Image.Source but why not bind back ListBox.SelectedItem and then you can refer to your object instead.

If you want to update Image1.Source with SelectedItem image then your SelectionChange method should look like this:

Image1.Source = ((sender as ListBox).SelecteItem as img).Imgs;