Comments are a feature in Excel for attaching explanatory notes to individual cells. Threaded comments, on the other hand, support multi-user discussions and replies.

Working with Cell Comments

Creating Comments

This code snippet creates a new workobok, accesses the active sheet, and adds comments to three cells.

import com.grapecity.documents.excel.*;

public class ExcelCommentExample {
    public static void main(String[] args) {
        Workbook workbook = new Workbook();
        IWorksheet activeSheet = workbook.getActiveSheet();

        activeSheet.getRange("B2").addComment("Comment for cell B2");
        activeSheet.getRange("C5").addComment("Comment for cell C5");
        activeSheet.getRange("E7").addComment("Comment for cell E7");

        workbook.save("CellComments.xlsx");
    }
}

Executing this code generates an Excel file where cells B2, C5, and E7 have a small red triangle indicator in their top-right corner. Hovering over the cell displays the comment text.

Modifying and Displaying Comments

Existing comments can be updated. The setVisible property can force a comment to remain visible without requiring a hover action.

Workbook workbook = new Workbook();
workbook.open("CellComments.xlsx");
IWorksheet targetSheet = workbook.getWorksheets().get(0);

// Update comment text
targetSheet.getRange("B2").getComment().setText("Updated comment for B2");
targetSheet.getRange("E7").getComment().setText("Updated comment for E7");

// Make the comment for C5 persistently visible
targetSheet.getRange("C5").getComment().setVisible(true);

workbook.save("ModifiedComments.xlsx");

Deleting Comments

To remove a comment from a cell, call the delete method on the IComment object.

Workbook workbook = new Workbook();
workbook.open("CellComments.xlsx");
IWorksheet sheet = workbook.getActiveSheet();

sheet.getRange("B2").getComment().delete();
sheet.getRange("C5").getComment().delete();
sheet.getRange("E7").getComment().delete();

workbook.save("ClearedComments.xlsx");

After deletion, the red triangle indicators are removed, and the comment data is permanently deleted from the file.

Working with Threaded Comments

Threaded comments support conversation-like interactions, allowing an initial comment and subsequent replies from different authors.

Creating a Threaded Comment with a Reply

Workbook wb = new Workbook();
IWorksheet ws = wb.getActiveSheet();

// Add a threaded comment with an author name
ICommentThreaded commentThread = ws.getRange("F10").addCommentThreaded("Initial project estimate.", "Manager");

// Add a reply to the thread
commentThread.addReply("Needs revision based on new scope.", "Analyst");

wb.save("ThreadedComments.xlsx");

The resulting Excel file will show a purple comment indicator in cell F10. Clicking on it opens a panel displaying the comment thread with the initial note and the reply, each tagged with its author.

Editing Threaded Comments

You can modify the text of the initial comment or any of its replies.

Workbook wb = new Workbook();
wb.open("ThreadedComments.xlsx");
IWorksheet ws = wb.getWorksheets().get(0);

ICommentThreaded thread = ws.getRange("F10").getCommentThreaded();

// Edit the main comment
thead.setText("Revised project estimate.");

// Edit the first reply in the thread
thread.getReplies().get(0).setText("Revised estimate approved.");

wb.save("EditedThreadedComments.xlsx");

Deleting Threaded Comments

The clearCommentsThreaded method removes the entire comment thread associated with a cell.

Workbook wb = new Workbook();
wb.open("ThreadedComments.xlsx");
IWorksheet ws = wb.getWorksheets().get(0);

// Remove all threaded comments from cell F10
ws.getRange("F10").clearCommentsThreaded();

wb.save("ClearedThreadedComments.xlsx");