VBScript in a Nutshell

Name

Terminate Event

Syntax

Private Sub Class_Terminate( )

Description

The Terminate event is fired when the last instance of an object or class is removed from memory.

Rules at a Glance

• The Terminate event applies to classes defined with the Class...End Class construct.

• Instances of a class are removed from memory by explicitly setting the object variable to Nothing or by the object variable going out of scope.

• If a script ends because of a runtime error, a class’s Terminate event isn’t fired.

Example

The following example shows a typical terminate event in a class object that decrements a global instance counter used to ensure that only a single instance of a particular utility object is created. When the counter reaches 0, the global object reference to the utility object is destroyed.

Private Sub Class_Terminate( )

    glbUtilCount = glbUtilCount - 1
    If glbUtilCount = 0 then
        Set goUtils = Nothing
    End If
    
End Sub

Programming Tips & Gotchas

• The Terminate event is designated in code as:

  Class_Terminate           ' Correct syntax

  This contrasts with the documentation, which incorrectly indicates that the event procedure should be designated as:

                          classname_Terminate       ' Incorrect syntax

  where classname is the name of the class whose Terminate event is being trapped.

• The Terminate event is also fired when the object variable holding a reference to the last instance of an object is re-referenced in a Set statement using the New keyword, or is assigned a reference to a new instance of the same type of object is explicity ...