Binding problem

[MBrekhof]

Code in the xaml page:

<Image Source="button_help.png">
<Image.GestureRecognizers>
<TapGestureRecognizer Tapped="SalarisHelpTapped" CommandParameter="{Binding .}" />
</Image.GestureRecognizers>
</Image>

on reloading (saving the page) after a change in the page I get this error: Xamarin.Forms.Xaml.XamlParseException has been thrown. Position 1:1907. Method SalarisHelpTapped does not have the correct signature.