Hello, Telerik Team!
I have a question about how to better incorporate SelectAll functionality inside RadComboBox.
I've implemented basic solution when some checkbox outside RadComboBox is binded to IsAllSelected property of DataItems property of ViewModel and I'm trying to implement the same inside RadComboBox, when the first item of popup items is doing select/unselect all.
When SelectAll checkbox is outside RadComboBox everything is simple:
But when I'm trying to implement within RadComboBox I cannot use default item template:
because SelectAll checkbox must binded to IsAllSelected property, not IsChecked. But this solvable by ItemTemplateSelector and item template for select all item will be:
I this case I must to explicitly add in data items collection the first "select all" fictionale item with some property which sill allow to distinct it from another data items in ItemTemplateSelector.
But first problem is that when we binding to IsChecked property we binding to property of data item, but when to IsAllSelected we must bind to property of collection of data items.
The second problem is this is not looking as a decent approach.
Maybe you may advise some better one?
This code is based on "checkablecombo-2.zip" solution from this thread.
Sorry for my English.
All the best!