Get the dialog from a MetroWindow

[saturne1606]

I need this because i need to fill InputDialog from a barcode scanner.
This function can be used outside from the MahApps.Metro namespace.
This can be modified to not use Reflection, but it should be merged in DialogManager.cs like this

public static async Task<TDialog> GetDialogAsync<TDialog>(MetroWindow owner) where TDialog : BaseMetroDialog
{
    TDialog dialog = null;
    await owner.Dispatcher.BeginInvoke(new Action(() =>
    {
        if (owner.metroDialogContainer.Children.Count != 0)
            dialog = owner.metroDialogContainer.Children[0] as TDialog;
    }));
    return dialog;
}

Sorry for my bad english...

[flagbug]

This PR doesn't build

[saturne1606]

I forgot using... :-( I will correct it

[saturne1606]

Sorry for failed PR.
I work a lot with await/async and don't know how to do the same without.
It finally builds.

[flagbug]

Can you please squash your commits and make the commit message more descriptive?

[punker76]

@saturne1606

Can you please squash your commits and make the commit message more descriptive?

[punker76]

added by 55c1de1