Exporting a HTML Table to Excel from ASP.NET MVC - asp.net

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
:)

Related

Multiple file download

ASP.NET/VB.NET web application.
Currently I'm creating a Word document and streaming it to the user. The browser handles this great with an "open/save" dialog, etc...
Basically the webform has a multi-select listbox. They select one or MORE documents and click the "Generate/Download" button. Works great for a single file. But multiple files doesn't work. Here's part of my code....
HttpContext.Current.Response.Clear()
HttpContext.Current.Response.AddHeader("Content-Disposition", Convert.ToString("attachment; filename=") & DocFileNameDestination)
HttpContext.Current.Response.AddHeader("content-length", finalDocumentStream.ToArray().Length.ToString())
HttpContext.Current.Response.ContentType = "application/ms-word"
HttpContext.Current.Response.BinaryWrite(finalDocumentStream.ToArray())
HttpContext.Current.Response.Flush()
HttpContext.Current.ApplicationInstance.CompleteRequest()
Question: How can I allow the user to download all selected files at one time. I would prefer a really simple solution. (Even if I have to create a zip... only if easier.)
Thanks in advance!
You can download them one at a time in a loop. If you want to download them all at once, you can download each one in a separate thread by starting a backgroundworker for each file in the loop.

asp.net - exporting table

I have a big problem with exporting my table to Excel file format.
Firstly I created code which runs on server and allows me to export data to Excel. Due to the fact that my table is created dynamically from the database there is nothing WITHIN the table at that stage, so no data were exported.
My second approach was targeting the final compiled table on the client side using either javascript or a very nice jQuery plugin called "DataTables" (www.datatables.net). Both of the attempts failed. Javascript seems to be to complex for me, plus it has difficulties running in Firefox, plugin on the other hand requires a very specific table structure which I am afraid I cannot provide.
So, a new idea of mine is: grab the page just after compiling and building it on the server, but before sending it to the browser. Target THE table and source its data using function on server. Finally export data to Excel, and send the page to the browser. Now. Is it possible? And if yes, then how?
I am beginner in programming world so any constructive suggestions and criticism would be highly appreciated. I would not mind any hard code examples ;)
You can try doing something like this:
protected void btnExport_Click(object sender, EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.ContentType = "application/vnd.ms-excel";
Response.Charset = "";
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
//if you're exporting a table put the table in a placeholder and render
//the placeholder to the text writer here
grdJobs.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}
What you need to do is export your query results in a .CSV file. CSV files can be opened in Excel no problem at all. http://wiki.asp.net/page.aspx/401/export-to-csv-file/ This shows you how to export into a .CSV format.
You're going to get a lot of suggestions instead of answers on this here. My recommendation would be to try the jQuery plugin: table2csv in order to create a more universal file format. But there are ways to target an actual Excel format, like this project.
If you want to export to actual XLS or XLSX instead of just CSV or something that just "opens" in Excel, there are third party tools that can help you with this. One example here:
http://www.officewriter.com

Working with big files in classic ASP

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.

Best method to populate XML from SQL query in ASP.NET?

I need to create a service that will return XML containing data from the database. So I am thinking about using an ASHX that will accept things like date range and POST an XML file back. I have dealt with pages pulling data from SQL Server and populating into a datagrid for visual display but never into XML for delivery, what is the best way to do this? Also if an ASHX and POST isn't the best method for delivery let me know... thanks!
EDIT: These answers are great and pointing me in the right direction. I should have also mentioned that the XML format has already been decided so I can't use any automatically generated one.
Combining linq2sqlwith the XElement classes, something along the lines:
var xmlContacts =
new XElement("contacts",
(from c in context.Contacts
select new XElement("contact",
new XElement
{
new XElement("name", c.Name),
new XElement("phone", c.Phone),
new XElement("postal", c.Postal)
)
)
).ToArray()
)
);
Linq2sql will retrieve the data in a single call to the db, and the processing of the XML will be done at the business server. This splits the load better, since you don't have the sql server doing all the job.
Have you tried DataSet.WriteXml()?
You could have this be the output of a web service call.
Sql Server 2005 and above has a "FOR XML AUTO" command that will convert your recordset to XML for you. Then you just have to return a string from your ASHX.
Beginning with SQL Server 2000, you can return query results as XML. For absolute control of them, use the "FOR XML EXPLICIT" command. You can use any format you desire that way.
http://msdn.microsoft.com/en-us/library/ms189068.aspx
It's as easy as writing your result to the raw output then. For added points, you can return the result set to a XPathDocument, pass it through an XSL transformation, and send the results out in any format you choose (HTML vs XML at the click of a button perhaps).
you can obtained that to a datatable and then call myTable.WriteXML()
if you are populating classes with the your database results then add the serializable attribute to the header your classes, and use the XMLSerializer
Converting an automatically generated format into a specified one is a job for xslt. Just find a way to run the output from the tool through an xslt filter.
Oracle has a great product for doing exactly this job - the oracle XDK. But it's a java thing, not ASP as far as I know.
For an example, this XHTML
http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql?pnid=2524
is generated automatically from this XML, which is generated by oracle
http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql?pnid=2524&xml-stylesheet=none
Of course, you are not after XHTML, but some other XML format. But XSLT will do the job.

How can I export my ASP.NET page to Excel?

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.

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