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Comments

Updated on Jun 9, 2026

Minimum Version	R2 2022

RadSpreadProcessing supports working with comments. Comments mark information about a cell's data and can have one or multiple Replies. All comments are stored in the Comments property of the worksheet, which is of type CommentCollection. This collection holds SpreadsheetComment objects that represent the comments. Each comment has the following members:

Properties:

CellIndex: Gets or sets the cell index the comment is assigned to.
Text: Gets or sets the text of the comment.
CreationDate: Gets or sets the date when the comment is created. Nullable.
Author: Gets or sets the author assigned to the comment.
Replies: Gets the comment replies. The list is sorted by CreationDate.
IsResolved: Gets or sets a value indicating whether the comment is resolved.

All of the above properties push a change to the undo stack when modified.

Methods:

AddReply: Adds a SpreadsheetCommentReply to the ReplySortedCollection. The collection is re-sorted by the reply's CreationDate in ascending order after adding an object.
RemoveReply: Removes the specified reply from the collection.

Working with CommentCollection

Adding Comments

To add a comment, specify the cell index to which the comment relates, the author, the text content, and the creation date. The creation date is optional and defaults to the current date and time.

Example 1: Add a Comment

CellIndex relatedCellIndex = new CellIndex(1, 1);
string author = "John Doe";
string text = "Comment Content";
DateTime creationDate = DateTime.Now;

worksheet.Comments.Add(relatedCellIndex, author, text, creationDate);

The previous snippet adds a comment in cell B2.

Removing Comments

To remove a comment, specify the comment instance. You can obtain this instance from the CommentCollection.

Example 2: Remove a Comment

SpreadsheetComment comment = worksheet.Comments[0];
worksheet.Comments.Remove(comment);

Replies

Each comment can be replied to, forming a thread of information. All replies are stored in the Replies property of the comment, which is of type ReplySortedCollection. This collection holds SpreadsheetCommentReply objects that represent the replies. The ReplySortedCollection has the following members:

Properties:

Count: Gets the number of elements contained in the ReplySortedCollection.

Methods:

Add: Adds a SpreadsheetCommentReply to the ReplySortedCollection. The collection is re-sorted by CreationDate in ascending order after adding an object. Requires an object of type SpreadsheetCommentReply and can be used for adding existing replies. For adding a new reply, use the SpreadsheetComment.AddReply() method.
Remove: Removes the specified SpreadsheetCommentReply object from the ReplySortedCollection.
RemoveAt: Removes the element at the specified index of the ReplySortedCollection.
Clear: Removes all elements from the ReplySortedCollection.
Contains: Determines whether an element is in the ReplySortedCollection.
CopyTo: Copies the entire ReplySortedCollection to a compatible one-dimensional array, starting at the specified index of the target array.

Example 3: Working with Replies

void MyProgram()
{
    Workbook workbook = new Workbook();
    Worksheet worksheet = workbook.Worksheets.Add();

    string text = "First Comment";
    CellIndex relatedCellIndex = new CellIndex(0, 0); // Cell A1
    AddCommentWithRepliesToWorksheet(worksheet, relatedCellIndex, text, 2); // First comment will have 2 replies

    relatedCellIndex = new CellIndex(1, 1); // Cell B2
    text = "Second Comment";
    AddCommentWithRepliesToWorksheet(worksheet, relatedCellIndex, text, 0); // Second comment will have 0 replies

    //Add existing reply using the Add() method of __SpreadsheetCommentReply__
    var firstComment = worksheet.Comments[0];
    var secondComment = worksheet.Comments[1];

    SpreadsheetCommentReply reply = firstComment.Replies[0];
    secondComment.Replies.Add(reply); // Copies reply #1 from firstComment to secondComment

    //Remove
    firstComment.Replies.Remove(reply);

    //Clear
    firstComment.Replies.Clear();

    //Contains
    firstComment.Replies.Contains(reply); // Returns false

    //CopyTo
    SpreadsheetCommentReply[] replyArray = new SpreadsheetCommentReply[1];
    secondComment.Replies.CopyTo(replyArray, 0);
}

void AddCommentWithRepliesToWorksheet(Worksheet worksheet, CellIndex relatedCellIndex, string commentText, int repliesCount)
{
    string authorName = "Jane Doe";
    DateTime creationDate = DateTime.Now;
    SpreadsheetComment comment = worksheet.Comments.Add(relatedCellIndex, authorName, commentText, creationDate);

    for (int i = 0; i < repliesCount; i++)
    {
        string replyText = "Reply #" + (i + 1);
        comment.AddReply(authorName, replyText, creationDate); // Add new reply using the SpreadsheetComment.AddReply() method 
    }
}

Events

Both CommentCollection and ReplySortedCollection expose the following events, which work identically for both types:

Changing: Occurs prior to changing the collection.
Changed: Occurs after the collection has changed.

The two events for both collections use similar enumeration types for event arguments, with two possible values:

Add: Used when adding a comment or reply.
Remove: Used when removing a comment or reply.

Example 4: Change the Author of a Comment upon Adding It to the CommentCollection Using the Changing Event

void Comments_Changing(object sender, ShapeCollectionChangingEventArgs<SpreadsheetComment> e)
{
    SpreadsheetComment comment = e.Shape;
    if (e.ChangeType == ShapeCollectionChangeType.Add)
    {
        comment.Author = "Comment Author";
    }
}

Example 5: Change the Author of a Reply upon Adding It to the ReplySortedCollection Using the Changing Event

void Replies_Changing(object sender, ReplySortedCollectionChangingEventArgs e)
{
    if (e.ChangeType == ReplySortedCollectionChangeType.Add)
    {
        e.Reply.Author = "Reply Author";
    }
}