Error when call OpenFileDialog on osx and linux

When I load OpenFileDialog on osx and Ubuntu, it has some problem. I use the following code to load OpenFileDialog:

var task = Task.Run(() =>
{
    OpenFileDialog openFileDialog = new OpenFileDialog
    {
        AllowMultiple = true
    };
    var outPathStrings = openFileDialog.ShowAsync();
    return outPathStrings;
});
var filelistStrings = task.GetAwaiter().GetResult();

It works normal on Windows. But when I run it on osx, it shows you are calling a method that can only be invoked from the UI thread. And on Ubuntu, it says GtkDialog mapped without a transient parent. This is discouraged.. And they all have no more response.

I think it may be because I did not load a MainWindow. I use the following code to start the application:

 var app = new Application();
AppBuilder.Configure(app)
    .UsePlatformDetect()
    .SetupWithoutStarting();

I want to know what is the actual reason for the problem and if I can use some way to avoid the problem.

[kekekeks]

@grokys I think we should make window parameter here mandatory. Right now it’s too error-prone to use, since not passing the parent window is too forgiving on Win32 which is the most common developer platform.

[kekekeks]

It’s fine to pass null as window, just don’t expect the dialog to show at any meaningful location (like on top of your window).