Comments

• Jul 10, 2019
• 6 minutes to read

The following topic describes how RichEditControl supports using comments in the document.

• Manage Comments Manually

  Insert, modify and delete the comments using the corresponding API.

• Operate Comments in the User Interface

  Provide end-users with a capability to manage comments in the UI.

Manage Comments Manually

Create a Comment

To create a comment to the document range, use the following API.

Member	Description
Paragraph.Range	Retrieves a range the given paragraph occupies.
SubDocument.FindAll	Finds all document ranges that contain the given expression or text string.
SubDocument.Comments	Provides access to the document’s collection of Comment instances.
CommentCollection.Create	Creates a new item in the CommentCollection.

The code snippet belows creates an empty comment associated with the specific phrase within the document.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/comments-simple-example-t474988

Form1.cs

//The target range is the specific phrase in the introduction's first paragraph
DocumentRange[] foundRanges = richEditControl.Document.FindAll("an extensive problem in hardware and architecture is the construction of the emulation of checksums", SearchOptions.None);
if (foundRanges.Length > 0)
{
    //Create a new comment
    Comment comment = richEditControl.Document.Comments.Create(foundRanges[0], "Johnson Alphonso D", new DateTime(2014, 4, 25));
}

Form1.vb

'The target range is the specific phrase in the introduction's first paragraph
Dim foundRanges() As DocumentRange = richEditControl.Document.FindAll("an extensive problem in hardware and architecture is the construction of the emulation of checksums", SearchOptions.None)
If foundRanges.Length > 0 Then
    'Create a new comment
    Dim comment As Comment = richEditControl.Document.Comments.Create(foundRanges(0), "Johnson Alphonso D", New Date(2014, 4, 25))
End If

Create a Nested Comment

The code snippet below demonstrates how to create a nested comment. To do that, use the CommentCollection.Create method with the passed parent comment.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/comments-simple-example-t474988

Form1.cs

Document document = richEditControl.Document;


if (document.Comments.Count > 0)
{
    //Create a new comment nested to the second comment in the collection
    Comment nestedComment = document.Comments.Create("Brian Zetc", DateTime.Now, document.Comments[1]);

    //Add text to the newly created comment
    SubDocument nestedCommentDocument = nestedComment.BeginUpdate();
    DocumentRange textRange = nestedCommentDocument.InsertText(nestedCommentDocument.CreatePosition(0),
    "Suffix trees are comprehensively reviewed in Wikipedia");
    nestedComment.EndUpdate(nestedCommentDocument);
}

Form1.vb

Dim document As Document = richEditControl.Document


If document.Comments.Count > 0 Then
    'Create a new comment nested to the second comment in the collection
    Dim nestedComment As Comment = document.Comments.Create("Brian Zetc", Date.Now, document.Comments(1))

    'Add text to the newly created comment
    Dim nestedCommentDocument As SubDocument = nestedComment.BeginUpdate()
    Dim textRange As DocumentRange = nestedCommentDocument.InsertText(nestedCommentDocument.CreatePosition(0), "Suffix trees are comprehensively reviewed in Wikipedia")
    nestedComment.EndUpdate(nestedCommentDocument)
End If

Edit the Comment

Edit the Comment Content

To accomplish this task, use the API from the table below.

Member	Description
Comment.BeginUpdate	Opens the given comment for modification.
SubDocument.InsertText	Inserts a text string to the specified position.
TableCollection.Create	Inserts a table to the specified position within the document.
ShapeCollection.InsertPicture	Inserts a floating picture to a given document position.
DocumentImageCollection.Insert	Inserts an inline image to the specified position.
ShapeCollection.InsertTextBox	Inserts a text box to the given position.
Comment.EndUpdate	Finalizes the comment update.

The following code sample adds text to the empty comment created earlier.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/comments-simple-example-t474988

Form1.cs

Document document = richEditControl.Document;

int commentCount = document.Comments.Count;
if (commentCount > 0)
{
    //The target comment is the first one
    Comment comment = document.Comments[0];
    if (comment != null)
    {
        //Open the comment for modification
        SubDocument commentDocument = comment.BeginUpdate();

        //Add text to the comment range
        commentDocument.InsertText(commentDocument.CreatePosition(0),
            "J. Taylor, Enabling Voice - over - IP and RAID with sofa,  in Proceedings of NOSSDAV, Oct. 1994.\r\n" +
            @"R.Tarjan, S.Shenker, J.Gray, A.Einstein, Q.Thomas, and X.Sato, ""Deconstructing operating systems with flanchedripper"", in Proceedings of INFOCOM, Mar. 2000.");

        //End the comment update
        comment.EndUpdate(commentDocument);
    }
}

Form1.vb

Dim document As Document = richEditControl.Document

Dim commentCount As Integer = document.Comments.Count
If commentCount > 0 Then
    'The target comment is the first one
    Dim comment As Comment = document.Comments(0)
    If comment IsNot Nothing Then
        'Open the comment for modification
        Dim commentDocument As SubDocument = comment.BeginUpdate()

        'Add text to the comment range
        commentDocument.InsertText(commentDocument.CreatePosition(0), "J. Taylor, Enabling Voice - over - IP and RAID with sofa,  in Proceedings of NOSSDAV, Oct. 1994." & ControlChars.CrLf & "R.Tarjan, S.Shenker, J.Gray, A.Einstein, Q.Thomas, and X.Sato, ""Deconstructing operating systems with flanchedripper"", in Proceedings of INFOCOM, Mar. 2000.")

        'End the comment update
        comment.EndUpdate(commentDocument)
    End If
End If

Edit the Comment Attributes

To change the comment parameters (author, date, etc.), use the following members.

Member	Description
Comment.BeginUpdate	Enables the comment modification.
Comment.Author	Specifies the comment’s author.
Comment.Date	Specifies the comment’s last modified date.
Comment.Name	Specifies the comment name.
Comment.EndUpdate	Finalizes the comment update.

The code snippet below changes the comment’s name, date and the author.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/comments-simple-example-t474988

Form1.cs

Document document = richEditControl.Document;
int commentCount = document.Comments.Count;

if (commentCount > 0)
{

    document.BeginUpdate();
    //The target is the second last comment
    Comment comment = document.Comments[document.Comments.Count - 1];

    //Change the comment's name, author and creation date
    comment.Name = "Reference";
    comment.Date = DateTime.Now;
    comment.Author = "Vicars Annie";
    document.EndUpdate();
}

Form1.vb

Dim document As Document = richEditControl.Document
Dim commentCount As Integer = document.Comments.Count

If commentCount > 0 Then

    document.BeginUpdate()
    'The target is the second last comment
    Dim comment As Comment = document.Comments(document.Comments.Count - 1)

    'Change the comment's name, author and creation date
    comment.Name = "Reference"
    comment.Date = Date.Now
    comment.Author = "Vicars Annie"
    document.EndUpdate()
End If

Delete the Comment

To remove a specific comment from the document, use the CommentCollection.Remove method as shown in the code snippet below.

C#

Document document = richEditControl.Document;
if (document.Comments.Count > 0)
  {
   //Remove the fourth document comment
   document.Comments.Remove(document.Comments[3]);
  }

VB.NET

Dim document As Document = richEditControl.Document
If document.Comments.Count > 0 Then
'Remove the fourth document comment
document.Comments.Remove(document.Comments(3))
End If

Operate Comments in the User Interface

Display Options

The comments are displayed in the Reviewing Pane or in balloons that appear in the document margins. The corresponding ranges are highlighted by a distinct color for each reviewer.

To change the comment displaying options, such as range highlighting color or comment visibility, use the CommentOptions‘s class properties.

Note

The CommentOptions.Visibility property set to Hidden changes its value to Visible after adding a new comment.

Comments Functionality in the Command UI

End-users can insert, modify or remove the desired comment using the Review Ribbon tab. To learn how to provide the application with the ribbon menu, refer to the How to: Create the RichEditControl with a Ribbon UI topic.

The Comment group on the Review tab allows end-users to insert new comments, remove existing one(s) and navigate through all the comments in the document.

The Tracking group buttons allow end-users to highlight comments in the document, to filter them by the author, to specify whether to display the comments in the document margins or show the Reviewing Pane.

To provide the application with the Reviewing Pane, in the designer mode, click the RichEditControl’s smart tag and select Create Reviewing Pane.

Tip

Adding new comments to the document can be forbidden. To do that, set the RichEditControl’s DocumentCapabilitiesOptions.Comments property to Disabled.