Develop Reference

Binding a ListBox to the elements of a collection in a collection

I have some problems binding a ListBox to the elements of a collection in a collection.. Let me explain:
I have a collection, ObservableCollection<Test> named testsCollection. Every test contains an ObservableCollection<LogEvent> named LogEvents. Every LogEvent has a Message that I need to display in the ListBox.
I need to display every "Message" in every "LogEvent" in every "Test". It has to be displayed in a flat list so I'm using a ListBox.
Here's a summary of what I tried:
DataContext = testCollection; // testCollection is an ObservableCollection<Test>
The I put this in the XAML:
<ListBox ItemsSource="{Binding LogEvents}" ItemTemplate="{StaticResource stepItemTemplate}">
Finally, here's the ItemTemplate, stepItemTemplate:
<DataTemplate x:Key="stepItemTemplate">
<TextBlock Text="{Binding Message}"></TextBlock>
</DataTemplate>
This "works" but it only displays the Messages in the LogEvents of the first Test. But I need to display every Messages of every LogEvent of every Test.. And I don't know what to try anymore :(

You should Usser ItemsControl when you want to bind a scenario like this
<ListBox ItemsSource="{Binding testsCollection}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Message}" FontSize="20" />
<ItemsControl ItemsSource="{Binding LogEvents}" Margin="0 20 0 0">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border BorderBrush="Blue" BorderThickness="2">
<TextBlock Text="{Binding Message}" FontSize="20" />
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>

A ListBox inside a stackpanel doesn't work

I have these controls:
<StackPanel>
<TextBlock Text="Bill Benson"/>
<Image Source="/Assets/Images/BB.png"/>
<ListBox>
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text=""/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<TextBlock Text="ends: 2015"/>
</StackPanel>
ListBox may have any number of items inside it. I want the whole page scroll from top to bottom, but it doesn't scroll down-up. How can I do that? I know the problem is because a scrollable control inside another scrollable one, but don't know how to fix it.

You need to assign the height to the listbox control, as it is taking an auto which means that the height keeps on increasing according to the count of items in it, so its impossible to access the items in the bottom of the control, So either give it a height or instead of stackpanel keep it in a grid with row definitions.
<StackPanel>
<TextBlock Text="Bill Benson"/>
<Image Source="/Assets/Images/BB.png"/>
<ListBox Height="200">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text=""/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<TextBlock Text="ends: 2015"/>
</StackPanel>

Try specifying a height for your controls, especially StackPanel and ListBox, even just an "Auto" Height could work for testing. Also, rather than setting an ItemTemplate, which would be more useful if you had a List of items to bind the ListBox to, try some hardcoded values:
<ListBox>
<TextBlock Text="1"/>
<TextBlock Text="Test"/>
<TextBlock Text="Another"/>
<TextBlock Text="testing"/>
<TextBlock Text="Sample"/>
</ListBox>
Try to add more than the ListBox can show, and see if it scrolls.

Try a dock panel instead:
<DockPanel>
<StackPanel DockPanel.Dock="Top">
<TextBlock Text="Bill Benson"/>
<Image Source="/Assets/Images/BB.png"/>
</StackPanel>
<TextBlock DockPanel.Dock="Bottom" Text="ends: 2015"/>
<ListBox>
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text=""/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DockPanel>
The ListBox will automatically expand to fill the space. Note: It has to be the last child in the DockPanel. (You can change this functionality using LastChildFill="False")

Find Index of Item in ItemsControl nested inside a LixtBox.Item

I have an ItemsControl nested inside a ListBox.ItemTemplate. The top ListBox is data-bound to an ObservableCollection. The collection is essentially a Purchase which contains Formulae which in turn contain individual products.
Now, if an individual product inside a formula is clicked, I would like it to be deleted from its formula. So, in the event handler, I should be able to determine the product's position using:
var index = [theItemsControl].ItemContainerGenerator.IndexFromContainer((sender as Button).TemplatedParent);
However, in my event handler, I do not how how to find the containing ItemsControl. I cannot give it a fixed name, since it is itself a part of a ListBox.ItemTemplate, meaning there will be multiple instances.
This is my XAML, stripped of any style-related stuff:
<ListBox x:Name="lbBasketFormulae" ItemsSource="{Binding Path=Purchase.Formulae}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<!-- Formula Title -->
<StackPanel Orientation="Horizontal">
<Label Width="30" Content="{Binding Path=Quantity}"></Label>
<Label Content="{Binding Path=FormulaType, Converter={StaticResource formulaTypeToNameConverter}}"></Label>
</StackPanel>
<!-- Formula Products -->
<ItemsControl ItemsSource="{Binding Path=Products}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button x:Name="bnBasketFormulaProduct" HorizontalContentAlignment="Left" Content="{Binding Path=Name}" Click="bnBasketFormulaProduct_Click">
<Button.Template>
<ControlTemplate TargetType="Button">
<TextBlock Text="{TemplateBinding Content}" />
</ControlTemplate>
</Button.Template>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
So, my question is: How do I find the position of my product inside my formula and the position of that formula inside the purchase, so that I can remove it from the ObservableCollection? (Changing the collection should then automatically reflect to the UI since it is data-bound.)
Many thanks in advance for any advice or hints!
Regards,
Chris

It is true that you should be able to do it via the viewmodel. But if you want you could use:
VisualTreeHelper.GetParent(myUserControl);

The answer is you don't find any positions of anything using ItemContainerGenerator.IndexFromContainer. Your problem is clearly taking place inside ViewModel and therefore you should seek for selected item or whatever inside your ViewModel and not in ListBox or code behind of Window.
Therefore I suggest you to create a proper ViewModel with proper Bindings.

How to show a list of items?

I need to show a list of tweets. each tweet can be highlighted programmatically and also I can add some new controls to the tweet item. and I am using data binding.
for my purpose above, I thought of using a LongListSelector but it is too buggy, and it seems that I can't access a collection of its items (can I?). what else is suitable for showing a list of items, each item can contain some other controls, and also supports binding? I don't see another thing in the toolbox? is there any ester egg?
It's windows phone 8 app.

You can use a ListBox
<ListBox Name="listboxTimeline" Width="450" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,5,0,5" >
<Button Click="btn1_Click" >
<StackPanel VerticalAlignment="Top">
<Image Name="image" Source="{Binding ImageSource}" />
</StackPanel>
</Button>
<StackPanel Width="337">
<TextBlock Text="{Binding UserName}" />
<TextBlock Text="{Binding Content}" TextWrapping="Wrap" />
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And then you can data bind to this from your CS page. ( The above code is just a sample)

ScrollViewer in a listbox

I´m filling a listbox with a specific data, the code works fine, but I need to add a scrollviewer to the listbox because there are many elements inside, I tried to use a ScrolViewer and put inside the listbox, but doesn't work, here is the code
<StackPanel x:Name="Sites" Grid.Row="1" Orientation="Vertical">
<ListBox x:Name="ListSites" >
<ListBox.ItemTemplate>
<DataTemplate>
<Button Width="460" Height="120" Click="click" Name="btn">
<Button.Content>
<StackPanel Orientation="Vertical" Height="100" Width="460">
<TextBlock Width="460" Name="txtname" FontSize="22" Text="{Binding name}" Height="40" Foreground="CadetBlue" />
<TextBlock Width="460" Name="txtUrl" FontSize="22" Text="{Binding Url}" Height="60"/>
</StackPanel>
</Button.Content>
</Button>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>

I fixed it, simply adding the Height property in the ListBox control

If the ListBox is not given infinite space for height then it should automatically scroll when items overflow its boundaries. For instance, if the second Grid row outside your stackpanel has explicit or 'star' height set, the scrollbar in the listbox will show up automatically.
See also: Silverlight: Difficulty with ScrollViewer

You shouldn't need to add a ScrollViewer to your ListBox. It will start scrolling when it runs out of room.
However, because you've put the ListBox inside a StackPanel it won't ever think it's run out of room because the StackPanel grows infinitely in the direction of it's orientation to accommodate its contents.
You'll need to use a different container for your ListBox.

<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Vertical"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>