ItemInvoked vs SelectionChanged - events

Question

In Windows UWP, what is the difference between the ItemInvoked and SelectionChanged events for a NavigationView? The API reference states
ItemInvoked
Occurs when an item in the menu receives an interaction such as a click or tap.
SelectionChanged
Occurs when the currently selected item changes.
It seems to me that SelectionChanged can detect when navigation occurs even by some method other than clicking a NavigationView.MenuItem, so would be the better, more encompassing option to use?
Or are there different use cases for each?

Answer 1

The main difference would be that the SelectionChanged event is executed only once, but if you click the selected item repeatedly, it is not fired. ItemInvoked on the other hand will execute each time an item is clicked even if it is selected already.
Also - SelectionChanged event will execute when you manually set SelectedItem in code.

Answer 2

Another thing that might be useful to note is that ItemInvoked fires before SelectionChanged when you click on a NavigationView item

Answer 3

I was recently struggling with this question and having a problem when using the SelectionChanged Event. Successive clicks on the same Menu Item yielded no result.
Then I found this blog post (https://blogs.msdn.microsoft.com/appconsult/2018/05/06/using-the-navigationview-in-your-uwp-applications/) which suggested using the ItemInvoked Event for the same reason given in answer #1.
This did not work for me as posted in the Blog but after changing the code to use the InvokedItemContainer Tag property the solution worked just fine.
I have included the test code I used to verify the solution.
private void NvTopLevelNav_ItemInvoked(NavigationView sender, NavigationViewItemInvokedEventArgs args)
{
if (args.IsSettingsInvoked)
{
contentFrame.Navigate(typeof(SettingsPage));
}
else
{
string navTo = args.InvokedItemContainer.Tag.ToString();
if ( navTo != null)
{
switch (navTo)
{
case "Nav_Home":
contentFrame.Navigate(typeof(HomePage));
break;
case "Nav_Shop":
contentFrame.Navigate(typeof(ShopPage));
break;
case "Nav_ShopCart":
contentFrame.Navigate(typeof(CartPage));
break;
case "Nav_Message":
contentFrame.Navigate(typeof(MessagePage));
break;
case "Nav_Print":
contentFrame.Navigate(typeof(PrintPage));
break;
}
}
}
}
<Grid>
<NavigationView x:Name="nvTopLevelNav"
Loaded="NvTopLevelNav_Loaded"
Margin="0,12,0,0"
SelectionChanged="NvTopLevelNav_SelectionChanged"
ItemInvoked="NvTopLevelNav_ItemInvoked"
IsTabStop="False"
Header="Lets Go Shopping">
<NavigationView.MenuItems>
<NavigationViewItem Icon="Home" Content="Home" Tag="Nav_Home" />
<NavigationViewItem Icon="Shop" Content="Shop" Tag="Nav_Shop" />
<NavigationViewItem Content="Shopping Cart" Tag="Nav_Cart">
<NavigationViewItem.Icon>
<FontIcon Glyph="[Insert Hex Decimal Value Here. See Segoe MDL2 below for details.]"/>
</NavigationViewItem.Icon>
</NavigationViewItem>
<NavigationViewItem Icon="Message" Content="Message" Tag="Nav_Message" />
<NavigationViewItem Icon="Print" Content="Print" Tag="Nav_Print" />
</NavigationView.MenuItems>
<Frame x:Name="contentFrame"></Frame>
</NavigationView>
</Grid>