WPF ListBox display last item differently - wpf

Question

I want to have a listbox, that allows the user to fetch lets say 20 items from the DB and displays a hint on the last row of the listbox if there are more items to be fetched. When the user clicks on this last row, additional items should be retrieved from the DB, until there aren't any more and the last line displays this information.
First:
listitem1
listitem2
...
listitem19
listitem20
Button: <get_more>
after button press:
listitem1
listitem2
...
listitem39
listitem40
Info: <no more items>
Could all this be done in XAML only?
What would be the best solution to implement this?

Answer 1

Dude -- Everything can be done with XAML :D
Following a MVVM approach, I'd recommend you to do the following:
1/ Getting started: A DockPanel
<DockPanel LastChildFill="True">
<Button DockPanel.Dock="Bottom" />
<ListBox />
</DockPanel>
2/ Bind your ListBox to an ObservableCollection in your ViewModel:
<ListBox ItemsSource="{Binding ListElements}" />
In the ViewModel:
private ObservableCollection<String> _listElements;
public ObservableCollection<String> ListElements
{
get { return _listElements; }
set { _listElements = value; }
}
3/ Bind your Button's content to a predefined String:
<Button Content="{Binding ButtonString}" />
In the ViewModel:
public String ButtonString
{
get
{
//There, define if there are any more things to display
}
}
4/ Your Button fires a Command launching a method, let's say GetMore() :
<Button Content="{Binding ButtonString}" Command="{Binding GetMoreCommand} />
In ViewModel:
private void GetMore()
{
//append to the _listElements new elements from the list
//Update the ButtonString if there are no more elements
}
And there you go!
(you can also, if needed, define a button removing things from the ObservableCollection for example)