Visual Studio Hacks [Electronic resources] نسخه متنی

Hack 9. Master Regions

Tag, expand, and collapse regions. Visual
Studio's regions let you make even the largest
source files become instantly readable.

Regions
are a valuable part of organizing your code and making it more
readable. Using regions, you can select a section of code that you
want to be able to logically group and also collapse. In this hack,
you will learn how to use regions in both C# and VB.NET and learn
about an add-in that makes working with regions even easier.

2.5.1. C# Regions

To
use regions in C#, you simply need to surround the code you want to
include in the region with #region and
#endregion. Optionally, you can also include a
string literal after #region that will be shown
when the region is closed. Figure 2-15 shows an
example of C# code surrounded by a region.

Figure 2-15. C# region expanded

Figure 2-16 shows this same region, except collapsed.

Figure 2-16. C# region collapsed

In C#, you can include regions anywhere in your source code file,
even inside of methods or properties. (Whether this is a good idea is
debatable.) Regions can also be nested inside of other regions.

2.5.2. VB.NET Regions

VB.NET
regions are a little bit different than C# regions. In VB.NET, you
surround the code that you want to include in the region with
#Region and #End Region. You
can also include a string after the #Region, but
in VB.NET, the string will need to be enclosed in quotes. Figure 2-17 shows an example of VB.NET code surrounded by
a region.

Figure 2-17. VB.NET region expanded

You might notice that in VB.NET, region tags are always moved to the
complete left of the document. In VB.NET, you can include regions
inside of other regions, but you can't include them
inside of methods or properties.

2.5.3. Region Strategy

Regions are best used to group similar
parts of your class. This makes finding a particular method or
property easier and also makes the file more readable, since sections
that you are not working with are hidden inside of a region. I am a
big fan of the idea that all code, except for namespace declarations
and using statements, should be in a region. Opening a file in which
all of the private member variables are grouped inside of a region,
the constructors in another region, the private methods in another
region, and the public properties in yet another region make it
extremely easy to find exactly what you are looking for. There are
times when this organization might not make the most sense though.
When implementing an interface, it is a good practice to group the
method and properties that are used to implement the interface into a
single region.

The best thing to do with regions is to define a standard for your
project and then be sure that all of your developers follow that
standard. A well-defined region strategy can make it easier to find
and understand files, whereas a poorly defined strategy can lead to
regions being more of a hindrance than benefit.

2.5.4. The Regions Add-in

To
enclose a piece of existing code in a
region, you need to find the top of the code, type in the
#region statement, and then find the bottom of the
code and type in the closing #endregion statement.
While this is not all that difficult, wouldn't it be
nice to be able to simply highlight a section of code and click a
button that adds that code to a region? That is where the Regions
Add-in comes into play. Using the Regions Add-in, you can select a
piece of code using the mouse or keyboard and then right-click and
select Add to New Region.

First, you will need to download and install the Region Add-in from
http://www.codeproject.com/dotnet/RegionsAddIn.asp.
After you have downloaded and installed the add-in, you will see two
new items on your right-click menu. These are shown in Figure 2-18. (These items will be visible only when you
have text selected.)

Figure 2-18. Regions Add-in menu items

If you select a block of code and then click the Add to New Region
item, you will see the dialog shown in Figure 2-19.

Figure 2-19. New Region Name dialog

After entering a name in the dialog box and clicking OK, the add-in
will wrap the selected code in a region using the name you entered.

You can also use the add-in to add code into an existing region.
Simply select a section of code and then right-click and choose the
Add to Existing Region menu item. You will then see the Regions
Dialog shown in Figure 2-20.

Figure 2-20. Regions Dialog

From the Regions Dialog, you can select the region you want to add
the selected code to or you can decide to add it to a new region and
click the Add New Region checkbox. This is particularly useful if you
are adding a new property to the class; instead of opening the
existing region and appending it to the end, you can write the
property anywhere you want and then select it and move it to that
region.

The Regions Add-in is a valuable tool that makes working with regions
even easier than it already is.