NotOverridable (Visual Basic)

Specifies that a property or procedure cannot be overridden in a derived class.

Remarks

The NotOverridable modifier prevents a property or method from being overridden in a derived class. The Overridable (Visual Basic) modifier allows a property or method in a class to be overridden in a derived class. For more information, see Inheritance Basics (Visual Basic).

If the Overridable or NotOverridable modifier is not specified, the default setting depends on whether the property or method overrides a base class property or method. If the property or method overrides a base class property or method, the default setting is Overridable; otherwise, it is NotOverridable.

An element that cannot be overridden is sometimes called a sealed element.

You can use NotOverridable only in a property or procedure declaration statement. You can specify NotOverridable only on a property or procedure that overrides another property or procedure, that is, only in combination with Overrides.

Combined Modifiers

You cannot specify Overridable or NotOverridable for a Private method.

You cannot specify NotOverridable together with MustOverride, Overridable, or Shared in the same declaration.

Usage

The NotOverridable modifier can be used in these contexts:

Function Statement (Visual Basic)

Property Statement

Sub Statement (Visual Basic)

See Also

Reference

MustOverride (Visual Basic)

Overridable (Visual Basic)

Overrides (Visual Basic)

Concepts

Inheritance Basics (Visual Basic)

Shadowing in Visual Basic

Other Resources

Modifiers (Visual Basic)

Keywords (Visual Basic)

Change History