C#把gird数据导出到excel

/// <summary>
        /// DataTable导出到Excel
        /// </summary>
        /// <param name="fileName">默认的文件名</param>
        /// <param name="dataTable">数据源,一个DataTable数据表</param>
        /// <param name="titleRowCount">标题占据的行数，为0则表示无标题</param>
        public void ExportExcel(string fileName, DevExpress.Xpf.Grid.GridControl gc, int titleRowCount)
        {
            string saveFileName = "";
            //bool fileSaved = false;
            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.DefaultExt = "xls";
            saveDialog.Filter = "Excel文件|*.xls";
            saveDialog.FileName = fileName;
            saveDialog.ShowDialog();
            saveFileName = saveDialog.FileName;
            if (saveFileName.IndexOf(":") < 0) return; //被点了取消
            Microsoft.Office.Interop.Excel.Application xlApp;
            try
            {
                xlApp = new Microsoft.Office.Interop.Excel.Application();

            }
            catch (Exception)
            {
                MessageBox.Show("无法创建Excel对象，可能您的机子未安装Excel");
                return;
            }
            finally
            {
            }

            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];//取得sheet1
            //写Title
            if (titleRowCount != 0)
                MergeCells(worksheet, 1, 1, titleRowCount, gc.Columns.Count, "test");

            //写入列标题
            for (int i = 0; i <= gc.Columns.Count - 1; i++)
            {
                worksheet.Cells[titleRowCount + 1, i + 1] = gc.Columns[i].Header.ToString();

            }
            //写入数值
            for (int r = 0; r <= gc.GetRowsAsync(0, gc.VisibleRowCount).Result.Count; r++)
            {
                for (int i = 0; i <= gc.Columns.Count - 1; i++)
                {
                    string cellValue1 = gc.GetCellDisplayText(r, gc.Columns[i]);
                    worksheet.Cells[r + titleRowCount + 2, i + 1] = cellValue1;
                }
                System.Windows.Forms.Application.DoEvents();
            }

            worksheet.Columns.EntireColumn.AutoFit();//列宽自适应
            Excel.Range rg = worksheet.Range[worksheet.Cells[2, 2], worksheet.Cells[gc.GetRowsAsync(0, gc.VisibleRowCount).Result.Count+1, 2]];
            rg.NumberFormat = "000000";

            if (saveFileName != "")
            {
                try
                {
                    workbook.Saved = true;
                    workbook.SaveCopyAs(saveFileName);
                    //fileSaved = true;
                }
                catch (Exception ex)
                {
                    //fileSaved = false;
                    MessageBox.Show("导出文件时出错,文件可能正被打开！n" + ex.Message);
                }

            }
            xlApp.Quit();
            GC.Collect();//强行销毁
            // if (fileSaved && System.IO.File.Exists(saveFileName)) System.Diagnostics.Process.Start(saveFileName); //打开EXCEL
            MessageBox.Show(fileName + "导出到Excel成功", "提示", MessageBoxButton.OK);
        }