Obsolete Window attributes

[TangDave]

Why are the following 3 lines added by default when adding a new Avalonia Window in Visual Studio?

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="400"

1. these 2 links no longer work - what's the point of including them if they don't lead anywhere?
2. does anyone need DesignWidth and DesignHeight ? Why not just use the actual Width and Height - the live preview uses these if DesignWidth and DesignHeight are missing. It seems inefficient to set both when changing Window height and width.

[maxkatz6]

these 2 links no longer work - what's the point of including them if they don't lead anywhere?

It's not just link. These are XML namespaces. They don't have to work in browser, they have to identify unique property sets. I.e. two properties with the same name can be defined in different XML namespaces.

does anyone need DesignWidth and DesignHeight ? Why not just use the actual Width and Height - the live preview uses these if DesignWidth and DesignHeight are missing. It seems inefficient to set both when changing Window height and width.

Valid point, DesignWidth/DesignHeight are optional and only used for convenience.
But this kind of code is easier to remove if you don't need, than add when you need.

[TangDave]

I just find it very odd to use an obsolete URL as a namespace. It could be replaced by "Foo" and it would make as much sense.

[timunie]

@TangDave that's by convention in xml. https://www.w3schools.com/XML/xml_namespaces.asp

[TangDave]

There are so many possible ways to form namespaces - very odd that they settled on meaningless or broken urls.