Let’s start from here… The AvalonControlsLibrary is just a Listview (with a GridView as view) that creates it’s GridViewColumns dynamically on runtime by looking at the properties(and their metadata) of the bound object. So how can you control the look of the columns if they are being generated dynamically? Well here we can use the power of WPF’s styling system. We can create a Style in a ResourceDictionary that does not have the x:Key set but only the TargetType. By doing so we will be setting the Style to all our GridViewColumns.
An example for this is setting a Style for the Headers. Here is the XAML to do so
Hope this helps :)
P.S For anyone using the DataGridView I would suggest to have a look at the new DataGrid control from Microsoft. It’s really really COOL!