Caliburn micro listbox multiple selection MVVM - wpf

Question

I have a ListBox containing Name. Now I need to select multiple items from ListBox.
ViewModel.CS
private Person selectedListOfPeople_;
public Person SelectedListOfPeople
{
get
{ return selectedListOfPeople_;}
set
{ this.SetProperty(ref selectedListOfPeople_, value, nameof(SelectedListOfPeople));}
}
private ObservableCollection<Person> listOfPeople_;
public ObservableCollection<Person> ListOfPeople
{
get { return listOfPeople_; }
set
{
this.SetProperty(ref listOfPeople_, value, nameof(ListOfPeople));
}
}
public ShellViewModel()
{
ListOfPeople = new ObservableCollection<Person>
{
new Person("ABC"),new Person("DEF"),new Person("GHI"),new Person("JKL")
};
}
public class Person : Screen
{
private string personName_;
public string PersonName
{
get { return personName_; }
set { this.SetProperty(ref personName_, value, nameof(PersonName)); }
}
public Person(string personName)
{
PersonName = personName;
}
private bool isSelected_;
public bool IsSelected
{
get { return isSelected_; }
set { this.SetProperty(ref isSelected_, value, nameof(IsSelected)); }
}
}
View.XAML
<Grid Width="500" Height="500" Background="LightBlue">
<ListBox x:Name="ListOfPeople" SelectionMode="Multiple" Height="300" Width="300" Margin="120,100,80,100">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding PersonName}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListBox>
in that SelectedListOfPeople is not called when the second item is selected in ListBox set to Multiple selections. How can I make sure that this event is raised every time the user makes a selection in ListBox?

Answer 1

One way of doing this would be to break from the convention available in that framework and bind the property manually.
But first you would need to update the property for multiselect in the view model
private ObservableCollection<Person> selectedListOfPeople;
public ObservableCollection<Person> SelectedListOfPeople {
get { return selectedListOfPeople; }
set { this.SetProperty(ref selectedListOfPeople, value, nameof(SelectedListOfPeople)); }
}
private ObservableCollection<Person> listOfPeople;
public ObservableCollection<Person> ListOfPeople {
get { return listOfPeople; }
set { this.SetProperty(ref listOfPeople, value, nameof(ListOfPeople)); }
}
public ShellViewModel() {
ListOfPeople = new ObservableCollection<Person> {
new Person("ABC"),
new Person("DEF"),
new Person("GHI"),
new Person("JKL")
};
SelectedListOfPeople = new ObservableCollection<Person>();
}
And then bind to the desired property in the view's XAML
<ListBox x:Name="ListOfPeople" SelectionMode="Multiple"
Height="300" Width="300" Margin="120,100,80,100"
SelectedItems = "{Bining SelectedListOfPeople}"
>
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding PersonName}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ListBox>
The convention will bind the items source or the ListBox and the manual binding of the SelectedItems will provided the desired behavior.