public void printAll(System.Data.DataTable dt, string SheetName)
        {

            //手动设置   
            int startrow = 2;//开始写数据的行数,写Datatable数据



            int iRows = 0;
            int iCols = 0;
            int iTrueCols = 0;

            Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
            Microsoft.Office.Interop.Excel.Workbook wb = app.Workbooks.Add(System.Reflection.Missing.Value);
            Microsoft.Office.Interop.Excel.Worksheet ws = null;
            if (wb.Worksheets.Count > 0)
            {
                ws = (Microsoft.Office.Interop.Excel.Worksheet)wb.Worksheets.get_Item(1);
            }
            else
            {
                wb.Worksheets.Add(System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value);
                ws = (Microsoft.Office.Interop.Excel.Worksheet)wb.Worksheets.get_Item(1);
            }

            if (ws != null)
            {
                if (SheetName.Trim() != "")
                {
                    ws.Name = SheetName;
                }

                iRows = dt.Rows.Count;　　　
                                               iTrueCols = dt.Columns.Count;　 //包含隐藏的列，一共有多少列
                iCols = dt.Columns.Count;
               

                string[,] dimArray = new string[iRows + 1, iCols];

                for (int j = 0, k = 0; j < iTrueCols; j++)
                {

                    dimArray[0, k] = dt.Columns[j].Caption ;
                    k++;
                    
                }

                for (int i = 0; i < iRows; i++)
                {
                    for (int j = 0, k = 0; j < iTrueCols; j++)
                    {

                        dimArray[i + 1, k] = dt.Rows[i][j].ToString();
                        k++;
                        
                    }
                }

                ws.get_Range(ws.Cells[startrow, 1], ws.Cells[iRows + startrow, iCols]).Value2 = dimArray;
                ws.get_Range(ws.Cells[startrow, 1], ws.Cells[startrow, iCols]).Font.Bold = true;
                ws.get_Range(ws.Cells[startrow, 1], ws.Cells[iRows + startrow, iCols]).Font.Size = 10.0;
                ws.get_Range(ws.Cells[startrow, 1], ws.Cells[iRows + startrow, iCols]).RowHeight = 14.25;
                ws.Columns.ColumnWidth =20;
              


                app.Cells[1, 2] = "库存报表";
                //app.Cells[1, 5] = "日期: " + when.ToShortDateString();
                ws.get_Range(ws.Cells[1, 1], ws.Cells[1, 3]).Font.Size = 20.0;
                ws.get_Range(ws.Cells[1, 1], ws.Cells[1, 3]).Font.Color = ColorTranslator.ToOle(Color.Red);


            }
            //设置禁止弹出保存和覆盖的询问提示框   
            app.DisplayAlerts =  true;
            app.AlertBeforeOverwriting = false;

            app.Visible = true;
            //app.Save("aaaa");
        }