asp.netdatatable到处excel问题

xuexijun1992 2015-12-28 09:36:02

想问一下，那个转化是怎么转的，我看网上不同格式的转法有好多，但不知道原理是啥，今天上班让导出，找代码找了一天。。晚上回来问问大神，以下是我今天摘得代码：

 public bool StreamExport(DataTable dt, string[] columns, string fileName, System.Web.UI.Page pages)

        {

            if (dt.Rows.Count > 65535) //总行数大于Excel的行数 

            {

                throw new Exception("预导出的数据总行数大于excel的行数");

            }

            if (string.IsNullOrEmpty(fileName)) return false;

            

            StringBuilder content = new StringBuilder();

            StringBuilder strtitle = new StringBuilder();

            content.Append("<html xmlns:o='urn:schemas-microsoft-com:office:office' xmlns:x='urn:schemas-microsoft-com:office:excel' xmlns='http://www.w3.org/TR/REC-html40'>");

            content.Append("<head><title></title><meta http-equiv='Content-Type' content=\"text/html; charset=gb2312\">");

            //注意：[if gte mso 9]到[endif]之间的代码，用于显示Excel的网格线，若不想显示Excel的网格线，可以去掉此代码

            content.Append("<!--[if gte mso 9]>");

            content.Append("<xml>");

            content.Append(" <x:ExcelWorkbook>");

            content.Append("  <x:ExcelWorksheets>");

            content.Append("   <x:ExcelWorksheet>");

            content.Append("    <x:Name>Sheet1</x:Name>");

            content.Append("    <x:WorksheetOptions>");

            content.Append("      <x:Print>");

            content.Append("       <x:ValidPrinterInfo />");

            content.Append("      </x:Print>");

            content.Append("    </x:WorksheetOptions>");

            content.Append("   </x:ExcelWorksheet>");

            content.Append("  </x:ExcelWorksheets>");

            content.Append("</x:ExcelWorkbook>");

            content.Append("</xml>");

            content.Append("<![endif]-->");

            content.Append("</head><body><table style='border-collapse:collapse;table-layout:fixed;'><tr>");



            if (columns != null)

            {

                for (int i = 0; i < columns.Length; i++)

                {

                    if (columns[i] != null && columns[i] != "")

                    {

                        content.Append("<td><b>" + columns[i] + "</b></td>");

                    }

                    else

                    {

                        content.Append("<td><b>" + dt.Columns[i].ColumnName + "</b></td>");

                    }

                }

            }

            else

            {

                for (int j = 0; j < dt.Columns.Count; j++)

                {

                    content.Append("<td><b>" + dt.Columns[j].ColumnName + "</b></td>");

                }

            }

            content.Append("</tr>\n");



            for (int j = 0; j < dt.Rows.Count; j++)

            {

                content.Append("<tr>");

                for (int k = 0; k < dt.Columns.Count; k++)

                {

                    object obj = dt.Rows[j][k];

                    Type type = obj.GetType();

                    if (type.Name == "Int32" || type.Name == "Single" || type.Name == "Double" || type.Name == "Decimal")

                    {

                        double d = obj == DBNull.Value ? 0.0d : Convert.ToDouble(obj);

                        if (type.Name == "Int32" || (d - Math.Truncate(d) == 0))

                            content.AppendFormat("<td style='vnd.ms-excel.numberformat:#,##0'>{0}</td>", obj);

                        else

                            content.AppendFormat("<td style='vnd.ms-excel.numberformat:#,##0.00'>{0}</td>", obj);

                    }

                    else

                        content.AppendFormat("<td style='vnd.ms-excel.numberformat:@'>{0}</td>", obj);

                }

                content.Append("</tr>\n");

            }

            content.Append("</table></body></html>");

            content.Replace(" ", "");

            pages.Response.Clear();

            pages.Response.Buffer = true;

            pages.Response.ContentType = "application/ms-excel";  //"application/ms-excel";

            pages.Response.Charset = "UTF-8";

            pages.Response.ContentEncoding = System.Text.Encoding.UTF7;

            fileName = System.Web.HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8);

            pages.Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);

            pages.Response.Write(content.ToString());

            //pages.Response.End();  //注意，若使用此代码结束响应可能会出现“由于代码已经过优化或者本机框架位于调用堆栈之上,无法计算表达式的值。”的异常。

            HttpContext.Current.ApplicationInstance.CompleteRequest(); //用此行代码代替上一行代码，则不会出现上面所说的异常。

            return true;