Xamarin Prism : Dependency Service Toast Message - xamarin

Question

I want to implement a Toast message on my Android app.
So I created in my shared code the interface :
namespace TravelApp.Renderers
{
public interface IToast
{
void show(string message);
}
}
Then I created on my Android project the interface implementation
[assembly:Dependency(typeof(TravelApp.Droid.Toast))]
namespace TravelApp.Droid
{
public class Toast : IToast
{
public void show(string message)
{
Android.Widget.Toast.MakeText(Android.App.Application.Context, message, ToastLength.Short).Show();
}
}
}
In my XAML file I used a pancakeview, when I tap on this view I want to display my toast Message :
<pancake:PancakeView x:Name="MyPancakecs" HorizontalOptions="EndAndExpand"
VerticalOptions="EndAndExpand"
CornerRadius="60"
HeightRequest="50"
WidthRequest="50"
BackgroundColor="{StaticResource BackgroundColor}"
Margin="0,0,60,0"
Padding="15"
>
<Image Source="TrayPlus"></Image>
<pancake:PancakeView.GestureRecognizers>
<TapGestureRecognizer Command="{Binding ToastMyToaster}"/>
</pancake:PancakeView.GestureRecognizers>
</pancake:PancakeView>
Then I register my container in a PlateformInitializer class in my android Project :
namespace TravelApp.Droid
{
public class PlatformInitializer : IPlatformInitializer
{
public void RegisterTypes(IContainerRegistry containerRegistry)
{
containerRegistry.Register<IToast,Toast>();
}
}
}
I added it in my App constructor in MainActivity.cs :
LoadApplication(new App(new PlatformInitializer())) ;
And then in my ViewModel I add a IToast object in my constructor:
namespace TravelApp.ViewModels
{
public class TravelListViewModel : BindableBase
{
private string _messageToast;
public string MessageToast
{
get { return _messageToast; }
set { SetProperty(ref _messageToast, value); }
}
public DelegateCommand ToastMyToaster;
public TravelListViewModel(INavigationService navigationService, ITravelRepository travelRepository, IToast Toaster)
{
this._navigationService = navigationService;
this._travelRepository = travelRepository;
this._messageToast = "Test Toaster";
this._toaster = Toaster;
this.ToastMyToaster = new DelegateCommand(ToastShow);
}
private void ToastShow()
{
this._toaster.show(MessageToast);
}
}
In my research I used this documentation : https://prismlibrary.com/docs/xamarin-forms/Dependency-Service.html
However when I run the code and tap on my pancakeview, there is no message displayed, I'm not even sure that the command is triggered...
I don't know if I needed to implement the IPlateformInitializer.
Thank you for your help,

Answer 1

Here is how I did it.
Shared Project
public interface IToast
{
void LongAlert(string message);
void ShortAlert(string message);
}
Android Project (Renderer)
You need to install CurrentActivityPlugin
[assembly: Dependency(typeof(AndroidToast))]
namespace yournamespace
{
public class AndroidToast : IToast
{
public void LongAlert(string message)
{
Toast.MakeText(CrossCurrentActivity.Current.Activity, message, ToastLength.Long).Show();
}
public void ShortAlert(string message)
{
Toast.MakeText(CrossCurrentActivity.Current.Activity, message, ToastLength.Short).Show();
}
}
}
Calling toast in my shared project
internal static void Toast(string message, bool isShort=false)
{
var toast = DependencyService.Get<IToast>();
if (toast != null)
{
if (!isShort)
toast.LongAlert(message);
else
toast.ShortAlert(message);
}
}
Somewhere in my viewModel / any where in Shared project
Helper.Toast("message here");