Template parameters

Article
03/18/2022

Applies to: Visual Studio Visual Studio for Mac

Note

This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

You can replace values in your template when the template is instantiated. To set up this functionality, use template parameters. Template parameters can be used to replace values such as class names and namespaces in the template. The template wizard that runs in the background when a user adds a new item or project replaces these parameters.

Declare and enable template parameters

Template parameters are declared in the format $parameter$. For example:

$safeprojectname$
$guid1$
$guid5$

Enable parameter substitution in templates

In the .vstemplate file of the template, locate the ProjectItem element that corresponds to the item for which you want to enable parameter replacement.
Set the ReplaceParameters attribute of the ProjectItem element to true.
In the code file for the project item, include parameters where appropriate. For example, the following parameter specifies that the safe project name is used for the namespace in a file:
```
namespace $safeprojectname$
```

Reserved template parameters

The following table lists the reserved template parameters that can be used by any template:

Parameter	Description
clrversion	Current version of the common language runtime (CLR).
ext_*	Add the `ext_` prefix to any parameter to refer to the variables of the parent template. For example, `ext_safeprojectname`.
guid[1-10]	A GUID used to replace the project GUID in a project file. You can specify up to 10 unique GUIDs (for example, `guid1`).
itemname	The name of the file in which the parameter is being used.
machinename	The current computer name (for example, Computer01).
projectname	The name provided by the user when the project was created.
registeredorganization	The registry key value from HKLM\Software\Microsoft\Windows NT\CurrentVersion\RegisteredOrganization.
rootnamespace	The root namespace of the current project followed by the subfolder of the current item, with slashes replaced by periods. This parameter applies only to item templates.
defaultnamespace	The root namespace of the current project. This parameter applies only to item templates.
safeitemname	Same as `itemname` but with all unsafe characters and spaces replaced by underscore characters.
safeitemrootname	Same as `safeitemname`.
safeprojectname	The name provided by the user when the project was created but with all unsafe characters and spaces removed.
targetframeworkversion	Current version of the target .NET Framework.
time	The current time in a format that's based on Windows user settings. One example of a time format is DD/MM/YYYY 00:00:00.
specifiedsolutionname	The name of the solution. When "create solution directory" is checked, `specifiedsolutionname` has the solution name. When "create solution directory" is not checked, `specifiedsolutionname` is blank.
userdomain	The current user domain.
username	The current user name.
webnamespace	The name of the current website. This parameter is used in the web form template to guarantee unique class names. If the website is at the root directory of the web server, this template parameter resolves to the root directory of the web server.
year	The current year in the format YYYY.

Note

Template parameters are case-sensitive.

Custom template parameters

You can specify your own template parameters and values, in addition to the default reserved template parameters that are used during parameter replacement. For more information, see CustomParameters element (Visual Studio templates).

Example: Use the project name for a file name

You can specify variable file names for project items by using a parameter in the TargetFileName attribute.

The following example specifies that an executable file's name uses the project name, specified by $projectname$ .

<TemplateContent>
    <ProjectItem
        ReplaceParameters="true"
        TargetFileName="$projectname$.exe">
            File1.exe
    </ProjectItem>
      ...
</TemplateContent>

Example: Use the safe project name for the namespace name

To use the safe project name for the namespace in a C# class file, use the following syntax:

namespace $safeprojectname$
{
    public class Class1
    {
        public Class1()
        { }
    }
}

In the .vstemplate file for the project template, include the ReplaceParameters="true" attribute when you reference the file:

<TemplateContent>
    <ProjectItem ReplaceParameters="true">
        Class1.cs
    </ProjectItem>
    ...
</TemplateContent>