Xamarin Forms Button Command doesn't fire after adding button effect - xamarin

Question

I have a button like this:
<Button Margin="0,20,0,0" Command="{Binding OnSkip}" BackgroundColor="{StaticResource Primary}" CornerRadius="2"
Text="Terms and Conditions of Use" VerticalOptions="End" TextColor="White">
<Button.Effects>
<effects1:ButtonClickEffect></effects1:ButtonClickEffect>
</Button.Effects>
</Button>
Upon adding the button effect inside the button, the 'OnSkip' command no longer fires and I'm not sure why.
The button click effect code is implemented as follows:
public class AndroidButtonClickEffect : PlatformEffect
{
protected override void OnAttached()
{
this.Control.Touch += this.Control_Touch;
}
private void Control_Touch(object sender, Android.Views.View.TouchEventArgs e)
{
if (e.Event.Action == MotionEventActions.Down)
{
this.SetColor(Android.Graphics.Color.Blue);
}
else if (e.Event.Action == MotionEventActions.Up)
{
this.SetColor(Android.Graphics.Color.LightBlue);
}
}
private void SetColor(Android.Graphics.Color color)
{
this.Control.SetBackgroundColor(color);
}
protected override void OnDetached()
{
this.Control.Touch -= this.Control_Touch;
}
}
Removing the button effect causes the command to fire again. Why does the button effect interfere with the command firing? Is there a way I can get the effect to invoke the desired command (generically so I can reuse the effect)?
Thanks.

Answer 1

In the main project, I added the following class, which binds the Command:
public class ButtonClickEffect : RoutingEffect
{
public ButtonClickEffect() : base("Framework.ButtonClickEffect") { }
public static readonly BindableProperty CommandProperty =
BindableProperty.Create("Command", typeof(ICommand), typeof(ButtonClickEffect));
public static ICommand GetCommand(BindableObject view)
{
return (ICommand)view.GetValue(CommandProperty);
}
public static void SetCommand(BindableObject view, ICommand value)
{
view.SetValue(CommandProperty, value);
}
public static readonly BindableProperty CommandParameterProperty =
BindableProperty.CreateAttached("CommandParameter", typeof(object),
typeof(ButtonClickEffect), (object)null);
public static object GetCommandParameter(BindableObject view)
{
return view.GetValue(CommandParameterProperty);
}
public static void SetCommandParameter(BindableObject view, object value)
{
view.SetValue(CommandParameterProperty, value);
}
}
The Android implementation was implemented as follows:
[assembly:ResolutionGroupName("Framework")]
[assembly:ExportEffect(typeof(AndroidButtonClickEffect), "ButtonClickEffect")]
namespace Framework.Droid.Effects
{
public class AndroidButtonClickEffect : PlatformEffect
{
protected override void OnAttached()
{
Control.Touch += Control_Touch;
}
private void Control_Touch(object sender, Android.Views.View.TouchEventArgs e)
{
if (e.Event.Action == MotionEventActions.Down)
{
SetColor(Color.LightBlue);
}
else if (e.Event.Action == MotionEventActions.Up)
{
SetColor(Color.Blue);
}
var command = ButtonClickEffect.GetCommand(Element);
command?.Execute(ButtonClickEffect.GetCommandParameter(Element));
}
private void SetColor(Color color)
{
Control.SetBackgroundColor(color);
}
protected override void OnDetached()
{
Control.Touch -= Control_Touch;
}
}
}
I then removed the 'Command' property from my button and replaced it as follows:
<Button Margin="0,20,0,0" BackgroundColor="{StaticResource Primary}" CornerRadius="2"
Text="Terms and Conditions of Use" VerticalOptions="End" TextColor="White"
effects1:ButtonClickEffect.Command="{Binding OnSkip}" effects1:ButtonClickEffect.CommandParameter="{Binding .}">
<Button.Effects>
<effects1:ButtonClickEffect></effects1:ButtonClickEffect>
</Button.Effects>
</Button>
In all honesty, the command binding is a lot more awkward now (all this code just to get a simple button effect), but the important thing is that it now works. Now I need to work out how implement for iOS.
Credit from here for the answer and whoever posted this URL as an answer (it got deleted).