ListView isn't working properly with ObservableCollection - wpf

Question

Here's the code I'm working with. In xaml I've expanded the ListView like this:
<ListView x:Name="lv" ItemsSource="{Binding}">
<ListView.InputBindings>
<MouseBinding MouseAction="LeftDoubleClick" Command="{Binding Edit}" CommandParameter="{Binding SelectedItem, ElementName=lv}"/>
<KeyBinding Key="Return" Command="{Binding Edit}" CommandParameter="{Binding SelectedItem, ElementName=lv}"/>
</ListView.InputBindings>
</ListView>
and implemented INotifyPropertyChanged in Master class to see updates in ListView when I edit an item. In Person class I've added one more Command
public Command Edit { get; set; }
intialized it in constructior:
Edit = new Command(CanClick, EditItem);
and implemented those callbacks like this:
bool CanClick(object arg) => Count > 0;
void EditItem(object obj) {
if(obj != null{
var item = obj as Master;
item.FirstName = "Edited";
item.LastName = "Edited";
SetItem(IndexOf(item), item);
}
}
When I select an item and hit Return it updates the collection BUT I don't see any change in ListView. If I double click on an item, it neither updates the collection nor the ListView!
Another question is why do I have to set a name for the ListView to use in nested InputBindings like this ElementName=lv? Can I get rid of that?
EDIT
If I expand the ListView further like this:
<ListView x:Name="lv" ItemsSource="{Binding}">
<ListView.View>
<GridView>
<GridViewColumn Header="First Name" Width="200"
DisplayMemberBinding="{Binding FirstName}"/>
<GridViewColumn Header="Last Name" Width="200"
DisplayMemberBinding="{Binding LastName}" />
</GridView>
</ListView.View>
<ListView.InputBindings>
<MouseBinding MouseAction="LeftDoubleClick" Command="{Binding Edit}" CommandParameter="{Binding SelectedItem, ElementName=lv}"/>
<KeyBinding Key="Return" Command="{Binding Edit}" CommandParameter="{Binding SelectedItem, ElementName=lv}"/>
</ListView.InputBindings>
</ListView>
ListView reflects the update I make through void EditItem(object obj) BUT MouseBinding doesn't work in this way either. Why would one bind individual property like this for a collection?

Answer 1

There is no reason to call SetItem to update an item.
Setting the properties is enough provided that the Master class implements INotifyPropertyChanged correctly.
When it comes to handling double-clicks, you could add a reference to System.Windows.Interactivity and use an EventTrigger:
<ListView x:Name="lv" ItemsSource="{Binding}" xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity">
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseDoubleClick">
<i:InvokeCommandAction Command="{Binding Edit}" CommandParameter="{Binding SelectedItem, ElementName=lv}" />
</i:EventTrigger>
</i:Interaction.Triggers>
<ListView.View>
<GridView>
<GridViewColumn Header="First Name" Width="200" DisplayMemberBinding="{Binding FirstName}"/>
<GridViewColumn Header="Last Name" Width="200" DisplayMemberBinding="{Binding LastName}" />
</GridView>
</ListView.View>
</ListView>