Question

In VS2010 for a VB.NET 4.0 project, the IDE puts a green line under the last line in the following code:

Dim cityLocal As DateTime
cityLocal = externalFunction()
cityLocal.Today()

The suggested code replace is to update ‘cityLocal’ with ‘Date’. The reason is:
Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.

But it does compile and does work correctly. Is this just a bug in the VS2010?

Answer 1

Today is a shared member, thus should not (but can) be accessed through an instance of DateTime change your code to.

DateTime.Today

Although Visual Studio gives you suggestions to correct the “Error” it is infact a compiler warning, warning you that there is no need for an instance to access the shared member. You’ll find that it is not listed as an error in the error list. Which is why it compiles correctly.

The Visual Basic language specification states

9.2.4 Shared Methods

The Shared modifier indicates a method
is a shared method. A shared method
does not operate on a specific
instance of a type and may be invoked
directly from a type rather than
through a particular instance of a
type. It is valid, however, to use an
instance to qualify a shared method.

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=01EEE123-F68C-4227-9274-97A13D7CB433:

More information on the warning can be found in the documentation.

http://msdn.microsoft.com/en-us/library/y6t76186.aspx