Confirmation Dialog on back button press event Xamarin.Forms

Question

I am stuck at one point in Xamarin.Forms application

On Back button press simply I want to ask user to confirm whether he really wants to exit or not, \"OnBackButton

Answer 1

If you are on Mainpage and want to exit your app then this code will help you.

In your UI (PCL)

  protected override bool OnBackButtonPressed()
            {

                Device.BeginInvokeOnMainThread(new Action(async () => {
                    var result = await this.DisplayAlert("Alert!", "Do you really want to exit?", "Yes", "No");

                    if (result)
                    {
                        if (Device.RuntimePlatform == Device.Android)
                            DependencyService.Get().CloseApp();
                    }
                }));
                return true;
            }

Also create an Interface (in your UI PCL):

public interface IAndroidMethods
{
    void CloseApp();
}

Now implement the Android-specific logic in your Android project:

[assembly: Xamarin.Forms.Dependency(typeof(AndroidMethods))]
namespace Your.Namespace
{
   public class AndroidMethods : IAndroidMethods
   {
       public void CloseApp()
       {
             var activity = (Activity)Forms.Context;
            activity.FinishAffinity();
       }
   }
}