First statement of this 'Sub New' should be an explicit call to 'MyBase.New' or 'MyClass.New' because the '<constructorname>' in the base class '<baseclassname>' of '<derivedclassname>' is marked obsolete.

A class constructor does not explicitly call a base class constructor, and the implicit base class constructor is marked with the ObsoleteAttribute attribute and the directive to treat it as a warning.

When a derived class constructor does not call a base class constructor, Visual Basic attempts to generate an implicit call to a parameterless base class constructor. If there is no accessible constructor in the base class that can be called without arguments, Visual Basic cannot generate an implicit call. In this case, the required constructor is marked with the ObsoleteAttribute attribute, so Visual Basic cannot call it.

You can mark any programming element as being no longer in use by applying ObsoleteAttribute to it. If you do this, you can set the attribute's IsError property to either True or False. If you set it to True, the compiler treats an attempt to use the element as an error. If you set it to False, or let it default to False, the compiler issues a warning if there is an attempt to use the element.

By default, this message is a warning because the IsError property of ObsoleteAttribute is False. For information on hiding warnings or treating warnings as errors, see Configuring Warnings in Visual Basic.

Error ID: BC41003

To correct this error

  • Include a call to MyBase.New() or MyClass.New() as the first statement of the Sub New in the derived class.

See Also

Concepts

Attributes Used in Visual Basic

Application of Attributes