Show an DisplayAlert at App.cs (Xamarin)

Question

I am currently trying to constantly keep track whether the user is connected to internet or not.

I have the codes to check for connectivity and I want to be able to show a popup whenever the user is not connected to internet while using the app.

However, I can't put DisplayAlert at App.cs (Error: DisplayAlert does not exist in context).

May I know why is this so?

App.cs

public App()
{
    InitializeComponent();

    var seconds = TimeSpan.FromSeconds(1);
    Xamarin.Forms.Device.StartTimer(seconds,
        () =>
        {
            CheckConnection();
        });
}

private async void CheckConnection()
{
    if (!CrossConnectivity.Current.IsConnected)
        await DisplayAlert("No Internet Connection", "Please connect to Internet", "OK");
    else
        return;
}

Answer 1

DisplayAlert is a method of the page class. However your app has a 'MainPage' property. So as long as the main page is set (should always be so after it's set during startup) you can use

Application.Current.MainPage.DisplayAlert

or from within App.cs

MainPage.DisplayAlert

Answer 2

So you can do this, is working for me

Device.BeginInvokeOnMainThread(async () => { await Application.Current.MainPage.DisplayAlert("No Internet Connection", "Please connect to Internet", "OK"); });