OnSet()

OnSet(index, oldValue, newValue)

OnSet(index, ByRef oldValue, ByRef newValue)

Performs additional custom processes before setting a value in the MfCollectionBase instance.

Parameters

index

The zero-based index at which oldValue can be found.
Can be MfInteger instance or var integer.

oldValue

The value to replace with newValue.

newValue

The new value of the element at index.

Remarks

Protected Method.
The default implementation of this method is intended to be overridden by a derived class to perform some action before the specified element is set.

If the process fails, the collection reverts back to its previous state.

The default implementation of this method is an O(1) operation.

Notes to Implementers

This method allows implementers to define processes that must be performed before setting the specified element in the underlying MfList. By defining this method, implementers can add functionality to inherited methods without having to override all other methods.

OnSet() is invoked before the standard Set behavior, whereas OnSetComplete() is invoked after the standard Set behavior.

For example, implementers can restrict which values can be overwritten by performing a check inside OnSet().

OnValidate() is called prior to this method.