加入TapGestureRecognizer

範例程式

<Label Text="{Binding Extension}" Grid.Row="7" Grid.Column="2"  Style="{StaticResource ValueLabelStyle}">
  <Label.GestureRecognizers>
    <TapGestureRecognizer CommandParameter="{Binding .}" Tapped="OnExtTapped" NumberOfTapsRequired="1" />
  </Label.GestureRecognizers>  
</Label>

async void OnExtTapped(object sender, EventArgs e)
{
   var ext = (Label)sender;
   var text = ext.Text;
}

讀取CommandParameter資料

(1) 單一文字

var ext = (Label)sender;
var text = ext.Text;

(2) 物件

var eventArgsConvert = (TappedEventArgs)e;
var extClicked = eventArgsConvert.Parameter as Model.PhoneMyFavorite;

useful links

https://developer.xamarin.com/guides/xamarin-forms/user-interface/gestures/tap/