DisplayAlert crashes an app if executed in a page constructor

[alexeystrakh]

Description

DisplayAlert crashes an app if executed in a page constructor

public partial class MainPage: ContentPage
{
        public MainPage()
        {
            InitializeComponent();
            DisplayAlert("Hello", "There", "OK");
        }
}

Steps to Reproduce

1. Create a new MAUI app
2. Add DisplayAlert call to the MainPage constructor
3. Start the app and observe the app to crash on startup

Version with bug

Preview 12 (current)

Last version that worked well

Unknown/Other

Affected platforms

Windows

Affected platform versions

windows10.0.19041

Did you find any workaround?

Yes, if you execute the same method with a delay, it works just fine

public partial class MainPage: ContentPage
{
        public MainPage()
        {
            InitializeComponent();
            RenderDialog();
        }

        private async Task RenderDialog()
        {
            await Task.Delay(5000);
            await DisplayAlert("Hello", "There", "OK");
        }
}

Relevant log output

Faulting application name: xxx.exe, version: 1.0.0.0, time stamp: 0x61954b73
Faulting module name: KERNELBASE.dll, version: 10.0.19041.1466, time stamp: 0xe01c7650
Exception code: 0xc000027b
Fault offset: 0x000000000010b362
Faulting process id: 0x6390
Faulting application start time: 0x01d812fb09610291
Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll
Report Id: cc7145cf-2475-4e26-bdf6-e57bb709e481
Faulting package full name: 0A8834C6-F23D-4CEB-86B5-B57FD5D15D23_1.0.0.0_neutral__9zz4h110yvjzm
Faulting package-relative application ID: App

[jamesmontemagno]

Any reason you don't put it in the OnAppearing? This seems like a bad user experience as you can create a page at any time and it may not be visible at all.

I actually don't think this should be supported IMHO.

[Eilon]

Dup of #1514