Parameters
- nodedata
- the modified node data
- fromkey
- the key for the removed "from" node data
This is used for model update, when the model data has changed and the model itself needs to be updated to reflect those changes.
If the list of "from" keys implements System.Collections.Specialized.INotifyCollectionChanged the model will automatically call this method. Otherwise, you need to do so immediately after the value of FindFromNodeKeysForNode has changed.
This raises a Changed event with a value of ModelChange.RemovedFromNodeKey.