Inheriting WPF DataGrid might cause defaulting to OneTime databinding

I just ran into an annoying issue. I am extending WPF DataGrid copy and paste functionality similar to what is suggested by Vincent Sibal here.

public BetterDataGrid : DataGrid {…}

But when I did, data binding only worked against my initial view model. In my case a file load operation replaced the original view model and binding did not happen against the new view model.

I had to explicitly include Mode=TwoWay on the Binding, when using <this:BetterDataGrid … but this was not necessary when using <toolkit:Datagrid.

Just a warning, if you are going to extend DataGrid, be sure to explicitly set your binding mode.

XAML Comments in Attributes.

Sometimes I wish that XML supported comments in attributes instead of just <!—style.

Almost always this is a XAML file that I wish had this.

Today I realized just how silly I was being.

xmlns:mc=""  xmlns:d=""  mc:Ignorable="d"

And now I can just d:Anything=”any comment”.

Sure, I can’t nest my quotes there, but this is good enough for a lot of things.

<Grid d:Purpose=”this is the grid that contains the other grid that contains the things”>…