Visual Studio Hacks [Electronic resources] نسخه متنی

Hack 57. Insert Commonly Used Code Automatically

Discover an add-in that will provide code
templates and code completion to enable you to write code
faster.

Throughout this book, we have
talked about different ways to handle code snippets, including
storing them in the toolbox or using other add-ins to handle your
code snippets. The Code<Template>.NET
add-in allows you to create and manage code templates, which are code snippets that
contain variables. Instead of just having a piece of text you can
drag to your document, you will be able to specify variables that you
will be prompted for. What differentiates this add-in from other code
snippet management add-ins is the ability to define variables as well
as the ability to automatically insert your code template using a
predefined keyword and shortcut key.

Contrary to the misleading angle brackets, this add-in does not have anything to do with C++ templates or .NET 2.0 generics.

First you will need to download and install the
Code<Template>.NET add-in from http://www.codeproject.com/useritems/CodeTemplateNET.asp.
The installation is relatively painless, and the next time you start
Visual Studio you will see the CodeTemplate toolbar, which is shown
in Figure 6-18.

Figure 6-18. CodeTemplate toolbar

It is from this menu that you will work with the add-in. First,
let's add a new code template to the tool. Click
Open <codetmpl.cs> on the CodeTemplate menu. The
codetmpl.cs file contains all of the code templates
that this tool manages. It is to this file that you will need to add
your own code templates. As you can see, the format of this file is a
little confusinghere is a look at one of the standard code
templates:

#{Subsection Header|subh
///////////////////////////////////////////////////
// <%?Subsection name%>
}#

Each snippet starts with #{ and then the
name of the snippet, in this case Subsection
Header. After the name of the template is a
| character followed by a keyword,
which will be used to autoinsert the code into your document. What
follows next is the actual code that will be inserted into the
document. This can also include variables. In this case you see
<%?Subsection name%> in the text. When the
template is inserted, the add-in will prompt you with a dialog like
the one shown in Figure 6-19.

Figure 6-19. CodeTemplate variable dialog

This dialog allows you to specify the variable at the time of
insertion. The last part of the code template is the ending
}#. So let's add a new code
snippet to this file:

First you need to open the template and create a name and shortcut
key for it:

#{SQLConnection|sqlc

Next you need to specify the actual text that will be inserted,
including any variables:

SqlConnection sqlConn = new SqlConnection(
ConfigurationSettings.AppSettings["<%?ConfigKey%>"]);
using(sqlConn)
{
}

Then you need to close the template:

}#

Next you simply need to save the file, and the menu will be updated.

Now that the code template is added to the file, it can be invoked in
two different ways. The first is to select the code template from the
menu; the second is to type sqlc into the
document and then press Ctrl-Space (You may want to reassign this
shortcut key, as it tends to interfere with the normal Ctrl-Space
shortcut.) After performing either of these functions, you will be
presented with the variable dialog shown in Figure 6-20.

Figure 6-20. SQLConnection variable dialog

First, you need to specify the variable for this snippet. After you
press the OK button, the code shown here will be inserted into the
document.

SQLConnection sqlConn = new SQLConnection(
ConfigurationSettings.AppSetting["connString"]);
using(sqlConn)
{
}

As you can see, this add-in can help quickly insert code snippets,
including code snippets that include variables.

This add-in also includes a number of default
keywords that can be used in your
templates; these are used by enclosing the keyword between
<% and
%> characters. (Notice that, unlike
ConfigKey in the preceding example, there is no
question mark; those are used only for variables that will be
specified by the user.) You can insert any of the keywords shown in
Table 6-4 in the template, and the keyword will be
replaced with the value specified in the table.

The TEMPLATE keyword is particularly
interesting since it allows you to nest templates within each other.
Here is an example of how to use this keyword:

<%template:sqlc%>

This would insert the output from the template defined earlier into
another template. You will still be prompted for any variables when
the parent template is executed.

The Code<Template>.NET add-in is a great way to decrease the
amount of time you spend typing the same code over and over again.