Design Changes in Xamarin.Forms causes events to fail - xamarin

Question

If I create a new cross platform app and add a button to the default layout and add a click event then all behaves as expected. If I change the layout and place any other elements into the app then the events fail to fire. I am testing against a connected device but have also tried this on an emulator.
This works:
<StackLayout>
<!-- Place new controls here -->
<Button x:Name="Testbtn" Text="Click Me" />
<Label Text="Welcome to Xamarin.Forms!"
HorizontalOptions="Center"
VerticalOptions="CenterAndExpand" />
</StackLayout>
public MainPage()
{
InitializeComponent();
Testbtn.Clicked += OnClicked;
}
async void OnClicked(object sender, EventArgs e)
{
var btn = sender as Button;
await DisplayAlert("Test", String.Format("Clicked !! {0}", btn.Text), "OK");
}
When the layout is changed the app re-builds but the events do not fire...
<Grid Margin="5">
<Grid.RowDefinitions>
<RowDefinition Height="3.333" />
<RowDefinition Height="3.333" />
<RowDefinition Height="3.333" />
</Grid.RowDefinitions>
<StackLayout Grid.Row="2" >
<Button x:Name="btnTest" Text="Click Me" />
<Button x:Name="btnTest1" Text="And Another" />
</StackLayout>
</Grid>
public MainPage()
{
InitializeComponent();
Testbtn.Clicked += OnClicked;
Testbtn1.Clicked += OnClicked;
}
async void OnClicked(object sender, EventArgs e)
{
var btn = sender as Button;
await DisplayAlert("Test", String.Format("Clicked !! {0}", btn.Text), "OK");
}

Answer 1

Your buttons are named differently in XAML than what you refer to in the code behind. What you have is:
<Button x:Name="btnTest" Text="Click Me" />
<Button x:Name="btnTest1" Text="And Another" />
so the code behind should be:
btnTest.Clicked += OnClicked;
btnTest1.Clicked += OnClicked;
instead of:
Testbtn.Clicked += OnClicked;
Testbtn1.Clicked += OnClicked;