C#

private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            this.Application.DocumentChange += new ApplicationEvents4_DocumentChangeEventHandler(Application_DocumentChange);
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        private void Application_DocumentChange()
        {

            this.Application.ActiveDocument.TrackRevisions = true;
            int n = this.Application.ActiveDocument.Revisions.Count;
            Word.Range[] change = new Word.Range[n];
            for (int i = 0; i < n; i++)
            {
                change[i] = this.Application.ActiveDocument.Revisions[i].Range;
                change[i].Select();
                change[i].Copy();
                string changed = Clipboard.GetText(TextDataFormat.Text);
                MessageBox.Show(changed);
            }
        }

change[i] = this.Application.ActiveDocument.Revisions[i].Range;