adonisUI:Space throw error

[rasyidf]

Describe the bug
The SpaceExtension causes error

'' is not a valid value for the 'System.Windows.Controls.Control.Padding' property on a Setter.

and make the WPF designer stopped working.

Reproduce

It's just randomly appear in designer. like this.

Additional context
I've resolved some of error this by adding this piece of code in App.xaml.cs:

protected override void OnStartup(StartupEventArgs e)
{
    base.OnStartup(e);
    AdonisUI.SpaceExtension.SetSpace(8, 8);
}

but still, it's not the solution right?

Is there any Fallback value for the SpaceExtension if something's not right?

[benruehl]

So it seems like the designer fails to evaluate this statement in the default style of ScrollViewer:

<Setter Property="Padding" Value="{adonisUi:Space 0.5}"/>

I don't know why it fails here. Interesting that your call of SetSpace(8, 8) makes it work.

Before I take a deeper look at this, can you please make sure that you are using the current version of Visual Studio with the latest XAML Designer?
The designer received a major update a few months ago which might eliminate this issue.

[rasyidf]

I'm using 2 Version, the current Community Edition 16.5.4, and the Preview 3 Edition 16.6. both of them raise same problem

yes, I think the new designer is broken, and unfortunately there's no option to use legacy designer.

[benruehl]

I experimented a lot with the SpaceExtension but whenever I had a promising idea it turned out to have no effect on the errors. I was able to reproduce the exact same error you got but sometimes it just disappeared after changing absolutely nothing.

So I still have no clue what causes the error.

But I found out that changing

<Setter Property="Padding" Value="{adonisUi:Space 0.5}"/>

to

<Setter Property="Padding" Value="{adonisUi:Space 0.5, 0.5}"/>

... seemed to make the error disappear. Although the error sometimes did not re-appear when reverting this change. It's crazy, I know.

So I created a PR for this and we will see in the next release if it changes anything for you.

The PR contains another change as well that made sense to me but seemed to not have any effect. I included it anyways because it does no harm and might be useful to prevent similar errors.

I am not really satisfied with this solution but currently it is the best I have. Let's see how it performs. Feel free to re-open this issue when v1.16.0 is out in case you still receive the error.