Xamarin.Forms: How to Programmatically Open a Popup Page

Question

In my app, on initializing a page (let's call it FirstPage) I check for some conditions and, if necessary, want to display a warning page (let's call it WarningPage). The content of this page will be too complicated for Alert Boxes - with links and some formatting.

I tried to call Shell.Current.GoToAsync("WarningPage"); but I did not find the appropriate moment to do this. If called in OnAppearing(), WarningPage shows up after I close MainPage.

What I want is that the navigation stack contains FirstPage -> WarningPage -> (perhaps a third page by clicking on a link in WarningPage) and he gets back to FirstPage when he closes the WarningPage.

Edit: No errors occur in MainPage but WarningPage shows up after I close MainPage.

Answer 1

I seemed to solve it, but not for all cases: I use the Appearing event in FirstPage:

    public FirstPage()
    {
        InitializeComponent();
        this.Appearing += FirstPage_Appearing;
    }

In this event I useNavigation.PushModalAsync:

    private void FirstPage_Appearing(object sender, System.EventArgs e)
    {
        Navigation.PushModalAsync(new WarningPage());
    }

This does what I want but not really:

This works only for one of my pages, unfortunately not for the page where I actually need this feature. So - who can tell me a way that always works to programmatrically switch from one page to a second one and allow to use the Back function to go back to the first page?

When I have time, I'll try to find out under what circumstances it works and what I have to do otherwise.

Answer 2

it is not completely what I indended but I can live with a solution as decribed here.

Now the next question arises: In my solution the rest of the page is shifted down. I would like to have covered the remaining page by this popup.

This will be the next question in ths forum.