# Comments

**RadRichTextEditor** control provides functionality for inserting comment annotations inside the document. You can programmatically insert and delete comments though the [RadDocumentEditor](https://www.telerik.com/products/winforms/documentation/controls/richtexteditor/features/raddocumenteditor) class.

## UI and Commands

Commenting functionality is available in the **Review** tab inside the **RadRichTextEditorRibbonUI** example:

![WinForms RadRichTextEditor Comments Options](https://www.telerik.com/products/winforms/documentation/assets/49eb88b300ee8ea68f66d70a8f4a9268/richtexteditor-features-comments001.png)

The following commands related to the commenting functionality are available in the **Commands** property of the **RadRichTextEditor**:

* **InsertCommentCommand**: Adds a comment about the current selection.

* **DeleteCommentCommand**: Deletes the selected comment.

* **DeleteAllCommentsCommand**: Deletes all of the comments in the document.

* **GoToPreviousCommentCommand**: Navigates to the previous comment in the document.

* **GoToNextCommentCommand**: Navigate to the next comment in the document.

* **ToggleCommentsCommand**: Toggles comments visibility.

> tip In order to learn more about commands and how to use them refer to [this article](https://www.telerik.com/products/winforms/documentation/controls/richtexteditor/features/commands).

## Working with Comments Programmatically

Comments inside the **RadDocument** model are implemented using the **CommentRangeStart** and **CommentRangeEnd** annotations. The actual **Comment** object which contains the content of the comment is a property of the **CommentRangeEnd**.

Comments can be programmatically inserted/deleted using the following methods of **RadDocumentEditor**:

* **public void InsertComment(Comment comment)**

* **public void DeleteComment()**

* **public void DeleteComment(CommentRangeStart commentRangeStart)**

* **DeleteAllComments()**

Note, that these methods work with the current position and selection in the document.

You can also programmatically navigate and select comments using the API of **RadDocument**:

* **public CommentRangeStart GetNextComment()**

* **public CommentRangeStart GetPreviousComment()**

* **public CommentRangeStart GoToNextComment()**

* **public CommentRangeStart GoToPreviousComment()**

* **public void GoToComment(Comment comment)**

* **public void GoToComment(CommentRangeStart commentRangeStart)**

* **public CommentRangeStart GetCommentRangeStartByComment(Comment comment)**

There are also **GoToNextComment()** and **GoToPreviousComment()** methods available in **RadRichTextEditor**. They select the appropriate comment and place the focus inside the comment balloon if the comments are visible.  These methods also show a message box if no comment is found.

## Customizing Visualization

You can customize the looks of the comments by attaching to the **CommentShowing** event of **RadRichTextEditor**.   Inside the event handler you can access the **Comment** and modify the **AppearanceSettings** that are used to  visualize the comment. Here is an example:

```C#
private void radRichTextEditor1_CommentShowing(object sender, Telerik.WinForms.Documents.UI.CommentShowingEventArgs e)
{
    if (e.Comment.Author == "Boss")
    {
        e.AppearanceSettings.BorderBrush = System.Drawing.Brushes.Red;
        e.AppearanceSettings.BackgroundBrush = System.Drawing.Brushes.Orange;
        e.AppearanceSettings.HighlightColor = Telerik.WinControls.RichTextEditor.UI.Colors.Orange;
    }
    else
    {
        e.AppearanceSettings.BorderBrush = System.Drawing.Brushes.Green;
        e.AppearanceSettings.BackgroundBrush = System.Drawing.Brushes.LightGray;
        e.AppearanceSettings.HighlightColor = Telerik.WinControls.RichTextEditor.UI.Colors.LightGray;
    }
}
    
```

```VB.NET
    Private Sub radRichTextEditor1_CommentShowing(ByVal sender As Object, ByVal e As Telerik.WinForms.Documents.UI.CommentShowingEventArgs)
        If e.Comment.Author = "Boss" Then
            e.AppearanceSettings.BorderBrush = System.Drawing.Brushes.Red
            e.AppearanceSettings.BackgroundBrush = System.Drawing.Brushes.Orange
            e.AppearanceSettings.HighlightColor = Telerik.WinControls.RichTextEditor.UI.Colors.Orange
        Else
            e.AppearanceSettings.BorderBrush = System.Drawing.Brushes.Green
            e.AppearanceSettings.BackgroundBrush = System.Drawing.Brushes.LightGray
            e.AppearanceSettings.HighlightColor = Telerik.WinControls.RichTextEditor.UI.Colors.LightGray
        End If
    End Sub

```

And the result looks like this:

![WinForms RadRichTextEditor Comments Review](https://www.telerik.com/products/winforms/documentation/assets/d79d65d2b4eac3d563a04aaabfa484bf/richtexteditor-features-comments002.png)

Note, that for performance reasons this event will be thrown only once per each comment – the first time it is shown. The **AppearanceSettings** will then be cached and used for the associated comment when needed.

## See Also

* [RadDocumentEditor](https://www.telerik.com/products/winforms/documentation/controls/richtexteditor/features/raddocumenteditor)

* [Ribbon UI](https://www.telerik.com/products/winforms/documentation/controls/richtexteditor/ui-for-applying-rich-text-formatting/ribbon-ui)

* [Annotations](https://www.telerik.com/products/winforms/documentation/controls/richtexteditor/document-elements/annotations/overview)