int columnCount = dt.Columns.Count;
            int columnCount2 = dt2.Columns.Count;
            int columnCount3 = dt3.Columns.Count;

            //创建Excel对象
            Microsoft.Office.Interop.Excel._Application excelApp = new ApplicationClass();
            //新建工作簿
            Microsoft.Office.Interop.Excel._Workbook workBook = excelApp.Workbooks.Add(true);
            //新建工作表
            Microsoft.Office.Interop.Excel._Worksheet worksheet = workBook.ActiveSheet as Microsoft.Office.Interop.Excel._Worksheet;
            Microsoft.Office.Interop.Excel._Worksheet worksheet2 = workBook.ActiveSheet as Microsoft.Office.Interop.Excel._Worksheet;
            Microsoft.Office.Interop.Excel._Worksheet worksheet3 = workBook.ActiveSheet as Microsoft.Office.Interop.Excel._Worksheet;

            
            //设置表头
            for (int i = 0; i < columnCount; i++)
            {
                Range headRange = worksheet.Cells[2, i + 1] as Range;//获取表头单元格
                headRange.Value2 = dt.Columns[i].Caption;//设置单元格文本
            }
          

            //填充数据
            for (int i = 0; i < dt.Rows.Count - 1; i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    Range contentRange = worksheet.Cells[i + 3, j + 1] as Range;//获取单元格
                    contentRange.Value2 = dt.Rows[i][j].ToString().Trim();//设置单元格文本
                }
            }
           

            //保存导出的Excel
            
            string fileName = "E:\\测试" + ".xls";
            workBook.SaveCopyAs(fileName);
            workBook.Saved = true;