LongPressGestureRecognizer in Xamarin.Forms - xamarin

Question

I am applying gesture feature to my Label control. I have used this link- http://arteksoftware.com/gesture-recognizers-with-xamarin-forms/
I was able to get the LongPressGestureRecognizer event when i performed long press on label control.This event is getting called in renderer file.
I want to perform some operation in my shared code on LongPressGestureRecognizer event. so how can I detect this event in my shared code ? How to handle event handler to get this longpress event in my shared code ?

Answer 1

In your custom control declare command:
public class TappedGrid : Grid
{
public static readonly BindableProperty TappedCommandProperty =
BindableProperty.Create(nameof(TappedCommand),
typeof(ICommand),
typeof(TappedGrid),
default(ICommand));
public ICommand TappedCommand
{
get { return (ICommand)GetValue(TappedCommandProperty); }
set { SetValue(TappedCommandProperty, value); }
}
public static readonly BindableProperty LongPressCommandProperty =
BindableProperty.Create(nameof(LongPressCommand),
typeof(ICommand),
typeof(TappedGrid),
default(ICommand));
public ICommand LongPressCommand
{
get { return (ICommand)GetValue(LongPressCommandProperty); }
set { SetValue(LongPressCommandProperty, value); }
}
}
And then raise this command from renderer:
public class TappedGridRenderer : ViewRenderer
{
UITapGestureRecognizer tapGesturesRecognizer;
UILongPressGestureRecognizer longPressGesturesRecognizer;
protected override void OnElementChanged(ElementChangedEventArgs<View> e)
{
base.OnElementChanged(e);
tapGesturesRecognizer = new UITapGestureRecognizer(() =>
{
var grid = (TappedGrid)Element;
if (grid.TappedCommand.CanExecute(Element.BindingContext))
{
grid.TappedCommand.Execute(Element.BindingContext);
}
});
longPressGesturesRecognizer = new UILongPressGestureRecognizer(() =>
{
var grid = (TappedGrid)Element;
if (longPressGesturesRecognizer.State == UIGestureRecognizerState.Ended &&
grid.LongPressCommand.CanExecute(Element.BindingContext))
{
grid.LongPressCommand.Execute(Element.BindingContext);
}
});
this.RemoveGestureRecognizer(tapGesturesRecognizer);
this.RemoveGestureRecognizer(longPressGesturesRecognizer);
this.AddGestureRecognizer(tapGesturesRecognizer);
this.AddGestureRecognizer(longPressGesturesRecognizer);
}
}