How can I use a IValueConverter to bind the SelectedItems.Records collection in a custom summary?

Create a class that implements IValueConverter interface and create a static resource object of that class. Then, use a binding expression, which targerts with path the SelectedItems collection of the XamDataGrid (which depending on your structure, you can get with a RelativeSource or Elementname) and then apply the converter (static resource) at the Converter property of the Binding expression.

Sorry I try, but i don't understand how to do this.

I'have created a class that implements IValueConverter.
I'have a bind to the counter of the selected item. I'have attached the static class to the binding path.

But how can I use this in my Summary Calculator Class? Have you an example?

My Code

public static SelectedItemValueConverter selectedItemConverter = new SelectedItemValueConverter();

var bindCounter = new Binding
                                  {
                                      Path = new PropertyPath("SelectedItems.Records.Count"),
                                      ElementName = "datagrid",
                                      Converter = selectedItemConverter
                                  };

public override object EndCalculation(SummaryResult summaryResult)
{
            ????????
}

Ideas to solve the problem?

Thks.

Sacha