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Move data from itemsource of one listbox to another listbox wp8

I am parsing a RSS Feed from one site and storing it in listbox1 and then parsing another RSS storing it in listbox2. Now I want to combine the data of listbox1 and listbox2 in listbox3. It might sound silly but I am unable to do it. The main problem is I am not able to access the controls inside the listbox.
<ListBox x:Name="list1" ItemsSource="{Binding RSSData}" DataContext="{Binding RSSData}" Visibility="Collapsed">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock HorizontalAlignment="Center" x:Name="txtpubDate" Foreground="#FF170505" Text="{Binding Path=pubDate}" TextDecorations="Underline" ></TextBlock>
<TextBlock Padding="18" Foreground="#FF0E0101" x:Name="txtTitle" TextWrapping="Wrap" Text="{Binding Path=Title}" FontWeight="Bold"></TextBlock>
<Image Height="200" x:Name="imageLink" Source="{Binding strImg}"></Image>
<TextBlock Foreground="#FF0F0202" Padding="35" TextTrimming="WordEllipsis" HorizontalAlignment="Left" x:Name="txtDesc" Margin="2" TextWrapping="Wrap" Text="{Binding Path=Description,Converter={StaticResource RssTextTrimmer}}"></TextBlock>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
This is the XAML code of my listbox1 and I am trying to do it with listbox3.itemsource=listbox1.itemsource; but nothing is happening.
I also tried to add data in this way: listbox3.items.add(listbox.items[i])
but nothing is working.
Please help.

You can loop through the contents of the listbox and add them one by one for instance:
foreach(object item in listbox1.items)
{
listbox3.items.add(item);
}
and then do the same for listbox2.

WPF Adding an object to ListBox with existing ItemsSource

Hey I have a list box that I set the ItemsSource to be an ObservableCollection of objects from my database, and I need to add a single object at the end of this list. However I keep getting an invalid operation exception. Somehow my listbox is in use (which in my mind is a given as it is displayed and already have items inside.) Here is my code for the list box:
<ListBox x:Name="CarList" SelectionChanged="ItemSelected" ScrollViewer.HorizontalScrollBarVisibility="Disabled" Background="{x:Null}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel FlowDirection="LeftToRight" ItemHeight="300" ItemWidth="300"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="10,10">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="35" />
</Grid.RowDefinitions>
<Image Grid.Row="0" Source="{Binding image_path}" VerticalAlignment="Stretch"/>
<Grid Grid.Row="1" Background="SteelBlue">
<TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Margin="3" Text="{Binding model}"/>
<TextBlock HorizontalAlignment="Right" VerticalAlignment="Center" Margin="3" Text="{Binding price}"/>
</Grid>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
And I first set the ItemsSource like so:
CarList.ItemsSource = CarController.GetAllCars();
And then want to add my custom object like this:
ListBoxItem carAdd = new ListBoxItem();
carAdd.Content = new CarModel{ image_path = "/../Assets/add-512.png", id=-1};
CarList.Items.Add(carAdd);
But alas the last operation fails with this message:
Operation is not valid while ItemsSource is in use. Access and modify
elements with ItemsControl.ItemsSource instead.
I have looked for a few other suggestions but all use strings and single bindings in their examples and thus I haven't been able to figure out what exactly to do. If anyone got a suggestion it would be much appreciated.
-
Thanks.

You need to add the item to the items source, and the source should be observable so that the ListBox takes the new item into account:
var cars = new ObservableCollection<CarModel>(CarController.GetAllCars());
CarList.ItemsSource = cars;
...
var car = new CarModel{ image_path = "/../Assets/add-512.png", id=-1};
cars.Add(car);

Data Binding for nested controls

I want to do search inside some books, then result of each book appears in separate item of pivot control. each one is represented by a separate LongListSelector control inside that PivotItem. Now I want to know should I assing ItemsSource for LongListSelector or for its parent which is a Pivot?
There is a dictionary for all books:
private Dictionary<string, List<Model>> ItemResources = new Dictionary<string, List<Model>>();
and a List<Model> for each book, which will be saved as a value inside ItemResources above.
this is what I do:
foreach (var translation in ItemResources)
{
PivotItem pivotItem = new PivotItem
{
Header = translation.Key
};
LongListSelector lls = new LongListSelector
{
HideEmptyGroups = false,
IsGroupingEnabled = false
};
lls.ItemTemplate = Resources["template"] as DataTemplate;
lls.ItemsSource = translation.Value;
pivotItem.Content = lls;
ResultPivot.Items.Add(pivotItem);
}
and the template is a reusable DataTemplate which I redproduce it for each longlistselector inside each pivotItem of the ResultPivot:
<phone:PhoneApplicationPage.Resources>
<DataTemplate x:Key="template">
<StackPanel Margin="0,0,0,0" Orientation="Vertical">
<StackPanel Orientation="Horizontal" HorizontalAlignment="Left" Height="Auto" VerticalAlignment="Top" Width="455" Margin="3,20,3,0">
<TextBlock Text="{Binding Name}" TextWrapping="Wrap" Style="{StaticResource PhoneTextLargeStyle}" FontSize="{StaticResource PhoneFontSizeNormal}"/>
<TextBlock Text="{Binding Number}" TextWrapping="Wrap" Style="{StaticResource PhoneTextLargeStyle}" FontSize="{StaticResource PhoneFontSizeNormal}"/>
</StackPanel>
<StackPanel Height="Auto" VerticalAlignment="Top" HorizontalAlignment="Left" Width="455" Margin="3,0,3,20">
<TextBlock Text="{Binding Text}" TextWrapping="Wrap" Style="{StaticResource PhoneTextLargeStyle}" FontSize="{StaticResource PhoneFontSizeNormal}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</phone:PhoneApplicationPage.Resources>
The problem is that nothing appears on the screen after running. I saw in debugging, that the values are there, but it seems something is wrong with data binding. How can I solve it? thanks
(this is a Windows Phone 8 App, but because the concept is the same for WPF and its wide community I added it too)

The UI has currently no way of knowing when the source changes. You need to either use an ObservableCollection or implement the INotifyPropertyChanged interface to properly notify the UI when the source changes.

Binding data in C# and XAML?

I'm trying to use binding with C# and a XAML SemanticZoom control in my Metro app, but honestly I'm at a loss as to how to do it. Here's the XAML code I've gotten so far by piecing together from questions, articles, etc:
<SemanticZoom x:Name="boardZoom" Height="626" Margin="10,132,10,0" VerticalAlignment="Top">
<SemanticZoom.ZoomedInView>
<GridView IsSwipeEnabled="True" x:Name="ItemsGridView">
<GridView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="10,10,0,0"
HorizontalAlignment="Left" Background="White">
<TextBlock Text="{Binding Title}" TextWrapping="Wrap" Width="200" Height="300"
FontFamily="Global User Interface" FontSize="40" Foreground="Black"
VerticalAlignment="Center" HorizontalAlignment="Left"/>
<Image Source="{Binding Image}" Height="60" Width="60"
VerticalAlignment="Center" Margin="0,0,10,0" Visibility="{Binding isImage}" />
<TextBlock Text="{Binding Category}" TextWrapping="Wrap" Width="200"
FontFamily="Global User Interface" Foreground="Black"
VerticalAlignment="Center" HorizontalAlignment="Left"/>
</StackPanel>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
</SemanticZoom.ZoomedInView>
<!--Didn't include SemanticZoom.ZoomedOutView since I'm still trying to get the ZoomedIn one working first-->
</SemanticZoom>
And my C# code:
List<PinStore.pin> pins = PinStore.CopyFromStream(response.GetResponseStream()); //returns a list of PinStore.pin objects, which have name, type, Image, isImage, and Category objects
System.Collections.ObjectModel.ObservableCollection<SemanticZoomed.zoomedIn> toSource = new System.Collections.ObjectModel.ObservableCollection<SemanticZoomed.zoomedIn>(); //should I be using ObservableCollection or something like List<> here?
foreach (PinStore.pin pin in pins)
{
SemanticZoomed.ZoomedIn toAdd = new SemanticZoomed.ZoomedIn(); //class with Title, Image, isImage, and Category objects
if (pin.type == "text")
{
toAdd.Title = pin.name;
toAdd.Image = null;
toAdd.isImage = Visibility.Collapsed;
toAdd.Category = pin.category;
}
toSource.Add(toAdd);
}
ItemsGridView.DataContext = toSource;
I've not had much experience in XAML/C#, and zero experience with binding. I'm not getting any errors, but I've noticed that if I replace ItemsGridView.DataContext = toSource; with ItemsGridView.ItemsSource = toSource; a blank stackpanel shows up in the GridView, and I can't seem to find a way to fill that with the Title and Category values I specify. Thanks!

Well you should first consider creating a ResourceDictionary so you can save your item style. Then you can set the ItemStyle to the Resource Dictionary.
But regardless you need to do: ItemsGridView.ItemsSource = toSource; If you do not choose to Bind the toSource in the GridView xaml.
Also make sure the SemanticZoomed.zoomedIn object implements the INotifyPropertyChanged interface, And calls the event properly. And make sure the Title, Image, Category, etc are public properties that call the event when edited. and Also you need make sure pin.Text is an actual value. {Making sure}.
If you want to learn more about data binding check out how they do it in C# & XAML with Windows 8 {Should be the same thing}:
http://msdn.microsoft.com/en-us/library/windows/apps/xaml/hh464965.aspx

How to access a TextBlock within a ListBox with C#

For most of you, this might be an easy question, but I am a C# beginner (coming from VB) and would like to progam a Windows Phone App.
The question is: How can I access the TextBlock "LineOne" from code to change its width? For the page title, it works perfect with this (on orientation change):
this.PageTitle.Text = "Portrait";
However, something like this:
this.LineOne.width= "50";
won't work.
Why?
My XAML looks like this (almost the default data bound app from Visual Studio Express):
<!--TitlePanel -->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock x:Name="PageTitle" Text="Bundesliga" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>
<!--ContentPanel -->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<ListBox x:Name="MainListBox" Margin="0,0,-12,0" ItemsSource="{Binding Items}" SelectionChanged="MainListBox_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel x:Name="ListboxPanel" Margin="0,0,0,17" Width="432" Orientation="Horizontal">
<TextBlock x:Name="LineOne" Text="{Binding LineOne}" TextWrapping="Wrap" Style="{StaticResource PhoneTextNormalStyle}" Width="40" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
Thanks for your help!

You have to access the TextBlocks inside the listbox.
Something like:
TextBlock textblock = ListboxPanel.Items[index] as TextBlock;
textblock.Width = 50

IEnumerable<TextBlock> listtb = ListboxPanel.Items.TypeOf<TextBlock>();

The name can't be resolved as belonging to this as it belongs to the datatemplate. You can't refer to an item within a template (from outside that template) as there could be multiple items with that name and names must be unique.
If you are trying to change the style of the selected item you will likely find a better solution to be to use different visual states to represent this.
If you are trying to access a property which relates to the bound viewmodel you can cast the sender to the type of the viewmodel and access it's properties directly.