数据导到excel时出现Exception from HRESULT: 0x800A03EC的异常

运行如下代码时发现弹出Exception from HRESULT: 0x800A03EC异常

        private void ExportExcel(DataTable dt)
        {
            if (dt == null) return;
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();

            if (xlApp == null)
            {
                return;
            }
            System.Globalization.CultureInfo CurrentCI = System.Threading.Thread.CurrentThread.CurrentCulture;
            System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
            Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
            Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
            Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];
            Microsoft.Office.Interop.Excel.Range range;
            long totalCount = dt.Rows.Count;
            long rowRead = 0;
            float percent = 0;
            for (int i = 0; i < dt.Columns.Count; i++)
            {
                worksheet.Cells[1, i + 1] = dt.Columns[i].ColumnName;
                range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, i + 1];
                range.Interior.ColorIndex = 15;
                range.Font.Bold = true;
            }
            for (int r = 0; r < dt.Rows.Count; r++)
            {
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    worksheet.Cells[r + 2, i + 1] = dt.Rows[r][i];
                }
                rowRead++;
                percent = ((float)(100 * rowRead)) / totalCount;
            }
            xlApp.Visible = true;
        }

后Debug到worksheet.Cells[r + 2, i + 1] = dt.Rows[r][i];当数据含有"="后就弹出这个异常，把这名改为worksheet.Cells[r + 2, i + 1] = dt.Rows[r][i].ToString().Replace("=","");后运行正常，特记录下来。