Visual Basic 2005 in a Nutshell (In a Nutshell (OReilly))

Syntax

Global[.namespace...]

namespace (required)

The name of a top-level namespace, such as System or Microsoft, followed by additional namespace and type qualifiers

Description

New in 2005. The Global keyword provides a way to specify, without ambiguity, a namespace from the topmost level of the namespace hierarchy.

Normally, specifying a full namespace is unambiguous. However, it is possible to create situations where conflicts arise. Consider the following code.

Imports MyCompany Namespace MyCompany.System.Configuration Public Class Configuration ' ----- Class code here. End Class End Namespace Namespace MyCompany.MyProgram Public Module GeneralCode Public Sub SomeRoutine( ) ' ----- This next line is ambiguous. Dim whichOne As System.Configuration.Configuration End Sub End Module End Namespace

The Dim statement in this code is ambiguous because there are now two System.Configuration namespaces: one at the top and one within the MyCompany namespace, both of which contain a Configuration class.

To resolve this conflict, use the Global keyword to specify a full namespace from the very top of the hierarchy. Global appears just before all top-level namespaces. The two classes in this example can each be specified using the Global keyword as follows:

• Global.System.Configuration.Configuration

• Global.MyCompany.System.Configuration.Configuration

Version Differences

The Global keyword is new in Visual Basic 2005.

See Also

Continue Statement, On Error Statement