I am trying to export data to Excel from ASP.NET. The downloaded file is created on the fly when a link is clicked. The code that I use is something like this:
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
I am not exporting from a grid. I have a list of business objects that I want to loop through to export.
How do I have this file exported?
Thanks.
You really shouldn't be automating the Excel application in a server environment like ASP.NET. This MSKB article should be enough to scare you away from it: http://support.microsoft.com/kb/257757
OfficeWriter is a library for generating (and then streaming) Excel workbooks from ASP.NET that is intended for server use:
http://www.officewriter.com
Related
I need to access macro enable and external sourced excel 2003 calculator from asp.net web page. Excel accepts few values and returns some numbers post calculations.
Users are not allowed to amend/access the excel from office hence need web access to use the excel calculator features where user enter the values on webpage and pass to Excel and display results on webpage.
I tried to use sharepoint excel services due to macros's and external source on the excel file it fails excel services capability.
I would appreciate if anyone can point me in right direction
You can try EasyXLS Excel library. It can be integrated in ASP.NET web pages. It reads xls file macro enabled files and includes a calculator similar with the one from MS Excel.
// Create an instance of the class that read XLS files
ExcelDocument workbook = new ExcelDocument();
// Read XLS file
workbook.easy_LoadXLSFile("Excel macro enabled.xls");
// Get a sheet and compute the formulas
xlsWorksheet = (ExcelWorksheet) workbook .easy_getSheetAt(0);
String sError = xlsWorksheet.easy_computeFormulas(workbook, true);
// Check the result of the formula
String result = xlsWorksheet.easy_getExcelTable().easy_getCell(3,0).getFormulaResultValue();
To display the existing values and enter later other values you can use this code:
DataSet ds = workbook.easy_ReadExcelWorksheet_AsDataSet(xlsWorksheet);
and set the DataTable as data source for a GridView for example:
http://www.easyxls.com/manual/FAQ/import-excel-to-gridview.html
EasyXLS has also some open source code (more complex) for displaying an Excel file in ASP.NET pages that can be adjusted to your needs:
http://www.easyxls.com/excel-to-gridview
I have a requirement , where in I have to upload an .xlsx file on the server and then read the file into a data table using c# , asp.net.
I need to get your file onto the server.
I need to open the (uploaded?) file.
I need to read the contents of the file, applying any nessesary data parsing.
I need to display the results in a gridview.
Help would be appreciated.
I am currently working with ASP.NET MVC and I have an action method that displays few reports in the view in table format.
I have a requirement to export the same table to an Excel document at the click of a button in the View.
How can this be achieved? How would you create your Action method for this?
In your controller action you could add this:
Response.AddHeader("Content-Disposition", "filename=thefilename.xls");
Response.ContentType = "application/vnd.ms-excel";
Then just send the user to the same view. That should work.
I'm using component, called Aspose.Cells (http://www.aspose.com/categories/.net-components/aspose.cells-for-.net/).
It's not free, though the most powerful solution I've tried +)
Also, for free solutions, see: Create Excel (.XLS and .XLSX) file from C#
Get data from database using your data access methods in dot net.
Use a loop to get each record.
Now add each record in a variable one by one like this.
Name,Email,Phone,Country
John,john#john.com,+12345,USA
Ali,ali#ali.com,+54321,UAE
Naveed,naveed#naveed.com,+09876,Pakistan
use 'new line' code at the end of each row (For example '\n')
Now write above data into a file with extension .csv (example data.csv)
Now open that file in EXCEL
:)
I was wondering what's the best practise for serving a generated big file in classic asp.
We have an application with "export to excel" function that produces 10MB files. The excels are created by just calling a .asp page that has the Response.ContentType set to excel and has an HTML table for the data.
This gives as problem that it takes 4 minutes before the user sees the "Save as..." dialog.
My current solution is to call an .asp page that creates the excel on the server with AJAX and lets the page return the URL of the generated document. Then I can use javascript to display the on the original page.
Is this easy to do with classic asp (creating files on server with some kind of stream) while keeping security in mind? (URL should make people be able to guess the location of other files)
How would I go about handling deleted the generated files overtime? They have to be deleted periodicly as the data changes in realtime.
Thanks.
edit: I realized now that creating the file on the server will probably also take 4 minutes...
I think you are selecting a complex route, when the solution is simple enough (Though I may be missing some requirements)
If you to generate an excel, just call an asp page that do the following:
Response.clear
Response.AddHeader "content-disposition", "attachment; filename=myexcel.xls"
Response.ContentType = "application/excel"
'//write the content of the file
Response.write "...."
Response.end
This will a start a download process in the browser without needing to generate a extra call, javascript or anything
See this question for more info on the format you will choose to generate the excel.
Edit
Since Thomas update the question and the real problem is that the file take 4 minutes to generate, the solution could be:
Offer the user the send the file by email (if this is a workable solution in you server or hosting).
Generate the file async, and let the user know when the file generation is done (with an ajax call, like SO does when other user have added an answer)
To generate the file on the server
'//You should change for a random name or something that makes sense
FileName = "C:\temp\myexcel.xls"
FileNumber = FreeFile
Open FileName For Append As #FileNumber
'//generate the content
TheRow = "...."
Print #FileNumber, TheRow
Close #FileNumber
To delete the temp files generated
I use Empty Temp Folders a freeware app that I run daily on the server to take care of temp files generated. (Again, it depends on you server or hosting)
About security
Generate the files using random numbers or GUIds for a light protection. If the data is sensitive, you will need to download the file from a ASP page, but I think that you will be in the same problem again...(waiting 4 minutes to download)
Read file using FSO.
Set headers for Excel file-type, name according to file read and for download (attachment)
Flush response after headers are set. The client should display "save as" dialogue.
Output FSO to response. Client will download file and see progress bar.
How do you plan to generate the Excel? I hope you don't plan to call Excel to do that, as it is unsupported, and generally won't work well.
You should check to see if there are COM components to generate Excel that you can call from Classic ASP. Alternatively, add one ASP.NET page for the purpose. I know for a fact that there are compoonents that can be called from ASP.NET pages to do this. Worse come to worst, there's an Excel exporter component from Infragistics that works with their UltraWebGrid control to export. The grid need not be visible in order to accomplish this, but styles in the grid translate to styles in the spreadsheet. They also allow you to manipulate the spreadsheet programmatically.
How can I export the data in my webapp to an Excel sheet from ASP.NET (VB.NET,SQL 2005)?
change the contenttype of your ASP.Net page
Response.ContentType = "application/ms-excel"
One of my most popular blogs is how to generate an Excel document from .NET code, using the Excel XML markup (this is not OpenXML, it's standard Excel XML) - http://www.aaron-powell.com/linq-to-xml-to-excel
I also link off to an easier way to do it with VB 9.
Although this is .NET 3.5 code it could easily be done in .NET 2.0 using XmlDocument and creating the nodes that way.
Then it's just a matter to set the right response headers and streaming back in the response.
SpreadsheetGear for .NET will do it. You can find a bunch of live ASP.NET samples with C# & VB.NET source on this page.
Disclaimer: I own SpreadsheetGear LLC
If you can display your data in a GridView control, it inherently supports "right-click-->Export to Excel" without having to write any code whatsoever.
SQL Server Reporting services would be the best way to export data from an application into Excel.
If you dont have access to / dont wan't to use reporting services depending on the data you want to extract / format possibly using a CSV structure instead of Excel may be easiest.
Use the Microsoft.Office.Interop.Excel dlls to create excel files with your data and then provide links to download the files using Hunter Daley's download method...
As a general solution, you may want to consider writing handler (ashx) for exporting -- and pass either the query parameters to recreate the query to generate the data or an identifier to get the data from the cache (if cached). Depending on whether CSV is sufficient for your Excel export you could just format the data and send it back, setting the ContentType as #Hunter suggests or use the primary interop assemblies (which would require Excel on the server) to construct a real Excel spreadsheet and serialize it to the response stream.
I prefer to use a OLEDB connection string.
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Excel.xls;Extended Properties="Excel 8.0;HDR=Yes;IMEX=1";
Not sure about exporting a page but if you just want to export a dataset or datatable
HttpContext.Current.Response.Clear()
HttpContext.Current.Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", fileName))
HttpContext.Current.Response.ContentType = "application/ms-excel"
Dim sw As StringWriter = New StringWriter
Dim htw As HtmlTextWriter = New HtmlTextWriter(sw)
Dim table As Table = New Table
table.RenderControl(htw)
' render the htmlwriter into the response
HttpContext.Current.Response.Write(sw.ToString)
HttpContext.Current.Response.End()
I use almost the same exact code as CodeKiwi. I would use that if you have a DataTable and want to stream it to the client browser.
If you want a file, you could also do a simple loop through each row/column, create a CSV file and I guess provide a link to the client - you can use a file extension of CSV or XLS. Or if you stream the resulting file to the client it will prompt them if they want to open or save it to disk.
The interops are (well were last time I tried them) great for small datasets, but didn't scale well - horrifically slow for larger datasets.