Creating an Extension with an Editor Item Template

You can use item templates that are included in the Visual Studio SDK to create basic editor extensions that add classifiers, adornments, and margins to the editor. The editor item templates are available for Visual C# or Visual Basic VSIX projects.

Prerequisites

Starting in Visual Studio 2015, you do not install the Visual Studio SDK from the download center. It is included as an optional feature in Visual Studio setup. You can also install the VS SDK later on. For more information, see Installing the Visual Studio SDK.

Creating a Classifier Extension

The Editor Classifier item template creates an editor classifier that colors the appropriate text (in this case, everything) in any text file.

1. In the New Project dialog box, expand Visual C# or Visual Basic and then click Extensibility. In the Templates pane, select VSIX Project. In the Name box, type TestClassifier. Click OK.

2. In the Solution Explorer, right-click the project node and select Add / New Item. Go to the Visual C# Extensibility node and select Editor Classifier. Leave the default file name (EditorClassifier1.cs).

3. There are three code files, as follows:

   • EditorClassifier1.cs contains the EditorClassifier1 class.

   • EditorClassifier1ClassificationDefinition.cs contains the OEditorClassifier1ClassificationDefinition class.

   • EditorClassifier1Format.cs contains the EditorClassifier1Format class.

   • EditorClassifier1Provider.cs contains the EditorClassifier1Provider class.

4. Build the project and start debugging. The experimental instance of Visual Studio appears.

   If you open a text file, all the text is underlined against a violet background.

Creating a Text-Relative Adornment Extension

The Editor Text Adornment template creates a text-relative adornment that decorates all instances of the text character 'a' by using a box that has a red outline and a blue background. It is text-relative because the box always overlays the 'a' characters, even when they are moved or reformatted.

1. In the New Project dialog box, expand Visual C# or Visual Basic and then click Extensibility. In the Templates pane, select VSIX Project. In the Name box, type TestAdornment. Click OK.

2. In the Solution Explorer, right-click the project node and select Add / New Item. Go to the Visual C# Extensibility node and select Editor Text Adornment. Leave the default file name (TextAdornment1.cs/vb).

3. There are two code files, as follows:

   • TextAdornment1.cs contains the TextAdornment1 class.

   • extAdornment1TextViewCreationListener.cs contains the TextAdornment1TextViewCreationListener class.

4. Build the project and start debugging. The experimental instance appears. If you open a text file, all the 'a' characters in the text are outlined in red against a blue background.

Creating a Viewport-Relative Adornment Extension

The Editor Viewport Adornment template creates a viewport-relative adornment that adds a violet box that has a red outline to the top-right corner of the viewport.

To create a viewport adornment extension by using the Editor Viewport Adornment template

1. In the New Project dialog box, expand Visual C# or Visual Basic and then click Extensibility. In the Templates pane, select VSIX Project. In the Name box, type ViewportAdornment. Click OK.

2. In the Solution Explorer, right-click the project node and select Add / New Item. Go to the Visual C# Extensibility node and select Editor Viewport Adornment. Leave the default file name (ViewportAdornment1.cs/vb).

3. There are two code files, as follows:

   • ViewportAdornment1.cs contains the ViewportAdornment1 class.

   • ViewportAdornment1TextViewCreationListener.cs contains the ViewportAdornment1TextViewCreationListener class

4. Build the project and start debugging. The experimental instance appears. If you create a new text file, a violet box that has a red outline is displayed in the top-right corner of the viewport.

Creating a Margin Extension

The Editor Margin template creates a green margin that appears together with the words "Hello world!" below the horizontal scrollbar.

To create a margin extension by using the Editor Margin template

1. In the New Project dialog box, expand Visual C# or Visual Basic and then click Extensibility. In the Templates pane, select VSIX Project. In the Name box, type MarginExtension. Click OK.

2. In the Solution Explorer, right-click the project node and select Add / New Item. Go to the Visual C# Extensibility node and select Editor Viewport Adornment. Leave the default file name (EditorMargin1.cs/vb).

3. There are two code files, as follows:

   • EditorMargin1.cs contains the EditorMargin1 class.

   • EditorMargin1Factory.cs contains the EditorMargin1Factory class.

4. Build this project and start debugging. The experimental instance appears. If you open a text file, a green margin that has the words "Hello EditorMargin1" is displayed below the horizontal scrollbar.

See Also

Language Service and Editor Extension Points