static void richEditControl1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e) { RichEditControl richEdit = sender as RichEditControl; System.Drawing.Point docPoint = DevExpress.Office.Utils.Units.PixelsToDocuments(e.Location, richEdit.DpiX, richEdit.DpiY); DocumentPosition pos = richEdit.GetPositionFromPoint(docPoint); if (pos == null) { return; } string currentToolTipText = String.Format("Position: {0}, Character: {1}", pos.ToString(), richEdit.Document.GetText(richEdit.Document.CreateRange(pos, 1))); DevExpress.Utils.ToolTipControlInfo info = new DevExpress.Utils.ToolTipControlInfo(currentToolTipText, currentToolTipText); info.ToolTipPosition = System.Windows.Forms.Form.MousePosition; testToolTipController.ShowHint(info); }