Datasheet

Note that this check occurs when adding references; there is no check when you change this value to see

whether your updated value conﬂ icts with any existing references. Therefore, if you change this value,

then make sure you update any of your existing references to remove any that are part of .NET 4. You are

bound to have at least one because when the template creates your project it automatically adds a series of

references determined in part by the target framework speciﬁ ed when you created your application.

Debug Properties

The Express Edition of Visual Basic 2010 supports local debugging. This means it supports not only

the .NET - related Debug and Trace classes discussed in Chapter 6, but also actual breakpoints and the

associated interactive debugging available in all versions of Visual Studio. However, as noted, the full

versions of Visual Studio provide enhanced debugging options not available in Visual Basic 2010 Express

Edition. Figure 1 - 9 shows the project debugger startup options from Visual Studio 2010.

The default action shown is actually the only option available to Express users — which is to start the

current project. However, Visual Studio 2010 developers have two additional options. The ﬁ rst is to start

an external program. In other words, if you are working on a DLL or a user control, then you might want

to have that application start, which can then execute your assembly. Doing this is essentially a shortcut,

eliminating the need to bind to a running process.

FIGURE 1 - 9

Similarly for Web development, you can reference a speciﬁ c URL to start that Web application. This is often a

mixed blessing, as with ASP.NET 2.0, Visual Studio automatically attempts to start an ASP.NET application

based on the page you are currently editing. This is a change from ASP.NET 1.x, which allowed you to deﬁ ne

a start page. Because ASP.NET 2.0 does not use project ﬁ les, the new behavior was introduced. In most cases

it works just ﬁ ne, but if you have a Web application requiring authentication, then in most cases it makes

more sense to actually place that URL into the debug settings for your application.

However, developers have three options related to starting the debugger. The ﬁ rst is to apply command - line

arguments to the startup of a given application. This, of course, is most useful for console applications, but

in some cases developers add command - line parameters to GUI applications. The second option is to select a

different directory, a working directory, to be used to run the application. Generally, this isn ’ t necessary; but

it ’ s desirable in some cases because of path or permission requirements or having an isolated runtime area.

Visual Basic Keywords and Syntax

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