Code Snippets in Visual Studio 2010

Visual Studio allows developers to save snippets of code which can be inserted at a later time. This saves on retyping blocks of code that are used often. I also find it very useful when I have to show code during presentations. Instead of typing everything live, I find it far easier to simply add the code block by block using code snippets.

VS 2010 improves the snippet functionality, and makes it easier to create code snippets. There’s two types of snippets:
- Expansion snippets are inserted at the cursor
- SurroundsWith snippets wraps around selected code
 

Creating a Custom Snippet:

Let’s go ahead and create a try-catch-finally Expansion snippet:
- Insert a new XML file to the project and call it TryCatchFinally.snippet. Make sure the file name ends with .snippet
- Right-click on the editor window and select Insert Snippet->Snippet. This creates a basic XML snippet template as shown below:

<CodeSnippet Format="1.0.0"
             xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
  <Header>
    <Title>title</Title>
    <Author>author</Author>
    <Shortcut>shortcut</Shortcut>
    <Description>description</Description>
    <SnippetTypes>
      <SnippetType>SurroundsWith</SnippetType>
      <SnippetType>Expansion</SnippetType>
    </SnippetTypes>
  </Header>
  <Snippet>
    <Declarations>
      <Literal>
        <ID>name</ID>
        <Default>value</Default>
      </Literal>
    </Declarations>
    <Code Language="XML">
      <![CDATA[<test>
      <name>$name$</name>
      $selected$ $end$</test>]]>
    </Code>
  </Snippet>
</CodeSnippet>

- As you can see, by default the template contains both snippet types. Since I am creating an Expansion snippet, let’s go ahead and get rid of the <SnippetType>SurroundsWith</SnippetType> tag.
- Update the Title to "Try Catch Finally", Shortcut to "trycf" and Description to "Adds a try-catch-finally block".
- Literal tag enables us to define editable values that are inserted into the snippet. In the try-catch-finally snippet, we want to allow the user to change the type of the Exception being caught. The ID tag is the name of the editable value so change it to "ExceptionName". The Default tag specifies the default value for our editable field. I want to catch all exceptions, so change the Default tag’s value to "Exception".
- Finally, the code section contains what will be added when the snippet is inserted. Change the language to "CSharp", and the body to the following:

    <Code Language="CSharp">
      <![CDATA[
try
{
 
}
catch($ExceptionName$)
{
 
}
finally
{
 
}
      ]]>
    </Code>

- The final version of the TryCatchFinally.snippet file is shown below. For more details about the XML schema, take a look at the MSDN code snippets Schema Reference

<?xml version="1.0" encoding="utf-8" ?>
<CodeSnippet Format="1.0.0"
             xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">
  <Header>
    <Title>Try Catch Finally</Title>
    <Author>umair</Author>
    <Shortcut>trycf</Shortcut>
    <Description>Adds a try-catch-finally block</Description>
    <SnippetTypes>
      <SnippetType>Expansion</SnippetType>
    </SnippetTypes>
  </Header>
  <Snippet>
    <Declarations>
      <Literal>
        <ID>ExceptionName</ID>
        <Default>Exception</Default>
      </Literal>
    </Declarations>
    <Code Language="CSharp">
      <![CDATA[
try
{
 
}
catch($ExceptionName$)
{
 
}
finally
{
 
}
      ]]>
    </Code>
  </Snippet>
</CodeSnippet>

Loading the Snippet into Visual Studio:

There are two ways to insert the above snippet into Visual Studio.

The most straightforward way is to put the .snippet files in VS 2010's code snippets directory. The default location for it is C:\Users\<UserName>\Documents\Visual Studio 2010\Code Snippets\. This folder contains sub-directories based on the language of the snippet. For my example, the snippet goes under Visual C#. Once put here, VS 2010 automatically picks up the snippets without the need to restart.
 
The second option is to import the .snippet file into Visual Studio.
- Inside Visual studio, go to Tools->Code Snippets Manager (Ctrl+K,Ctrl+B). This brings up the Snippets Manager.
- Press Import button, and navigate to the location where the snippet was saved. Select the .snippet file.
- Press OK.
 

Using the Code Snippet:

Type the name of the snippet (the shortcut), and pressing tab expands it.

You can also press Ctrl+K and Ctrl+X which brings up the "Insert Snippet" menu as shown below:

We can navigate to My Code Snippets, and select the TryCatchFinally that we’ve just added: