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Learn more about: Inherits Statement
Inherits Statement
07/20/2015
vb.Inherits
Inherits
Inherits statement [Visual Basic]
Inherits statement [Visual Basic], syntax
9e6fe042-9af3-4341-8093-fc3537770cf2

Inherits Statement

Causes the current class or interface to inherit the attributes, variables, properties, procedures, and events from another class or set of interfaces.

Syntax

Inherits basetypenames

Parts

Term Definition
basetypenames Required. The name of the class from which this class derives.

-or-

The names of the interfaces from which this interface derives. Use commas to separate multiple names.

Remarks

If used, the Inherits statement must be the first non-blank, non-comment line in a class or interface definition. It should immediately follow the Class or Interface statement.

You can use Inherits only in a class or interface. This means the declaration context for an inheritance cannot be a source file, namespace, structure, module, procedure, or block.

Rules

  • Class Inheritance. If a class uses the Inherits statement, you can specify only one base class.

    A class cannot inherit from a class nested within it.

  • Interface Inheritance. If an interface uses the Inherits statement, you can specify one or more base interfaces. You can inherit from two interfaces even if they each define a member with the same name. If you do so, the implementing code must use name qualification to specify which member it is implementing.

    An interface cannot inherit from another interface with a more restrictive access level. For example, a Public interface cannot inherit from a Friend interface.

    An interface cannot inherit from an interface nested within it.

An example of class inheritance in the .NET Framework is the xref:System.ArgumentException class, which inherits from the xref:System.SystemException class. This provides to xref:System.ArgumentException all the predefined properties and procedures required by system exceptions, such as the xref:System.Exception.Message%2A property and the xref:System.Exception.ToString%2A method.

An example of interface inheritance in the .NET Framework is the xref:System.Collections.ICollection interface, which inherits from the xref:System.Collections.IEnumerable interface. This causes xref:System.Collections.ICollection to inherit the definition of the enumerator required to traverse a collection.

Example 1

The following example uses the Inherits statement to show how a class named thisClass can inherit all the members of a base class named anotherClass.

[!code-vbVbVbalrStatements#37]

Example 2

The following example shows inheritance of multiple interfaces.

[!code-vbVbVbalrStatements#38]

The interface named thisInterface now includes all the definitions in the xref:System.IComparable, xref:System.IDisposable, and xref:System.IFormattable interfaces The inherited members provide respectively for type-specific comparison of two objects, releasing allocated resources, and expressing the value of an object as a String. A class that implements thisInterface must implement every member of every base interface.

See also