Reading and parsing Excel files in C# - c#

What is the best way/library to read Excel 2003 and 2007 files using C#? I need to do some heavy parsing.

Do you need to parse the file, or deal with the contents?
For parsing the file, you'd better hope it's in Open Office XML format, because the previous binary version is not documented at all.
If you just need to deal with the contents, use the Office Interop libraries.

You can try SmartXLS for .Net,it support most features of excel(cell formatting,Charts,formulas,pivot tables etc),and can read/write both the excel97-2003 xls format and the excel2007 openxml format.

I would start by trying to use ADO.NET.
If that doesn't work, I used xlsio by Syncfusion.

If the data is in some kind of table format I'd suggest to try using OleDbConnection and treating the Excel sheet as another data connection. Otherwise Interop is ok if it's not on a server or anything like that.

You can use the MS Office interop assemblies (see here) to access Excel files from .NET applications.

There are a number of 3rd party tools you can use. I would avoid using the Interop libraries as they can be pretty slow. I have used Aspose.Cells before and it works pretty well. It does cost some money though.

Related

How to generate xls & xlsx from office 2003 xml spreadsheet programatically in c#

Currently our application exporting large data to office 2003 xml spreadsheet format in server.
The user can download the xml file.The file can be easily opened in office 03 and 07 correctly.
I want to know whether it is possible to create xls and xlsx format from this xml file in server and serve them to user?
[The server doesn't have office and neither will be.So interop is useless in this case.]
====== EDIT=====
Can't use third party solutions... :(
With your XML file, you could easily use XSLT to transform your XML into CSV. However, if you really need to export in native Excel spreadsheet types, it's probably a good idea to use a component.
Something we've used in the past, that I'd recommend, is Aspose.Cells – we've used this to generate Excel spreadsheets where plain CSV output wouldn't suffice (are you sure it won't suffice in your case - XSLT will make short work of that).
Whilst it's not free, it saves having to install Office on the server (and avoid using Office Automation etc.) and has very good support.
Edited following comments:
If you can't use third party components, if you can't install Office on the server, and you can't use interop, then – unless you want to get comfortable and read the Excel Binary File Format (.xls) Structure Specification as provided by Microsoft – the answer is a very short one: no.
If I understand your question corretly, you are not just serving 'pure' XML, but SpreadsheetML that is interpreted by Excel just as an ordinary Excel-file in binary format. So your users already have a very nice solution. How do are you creating those files? I use an XSLT to transform my XML-data to SpreadsheetML that is just a specific XML-format. In that way I can do anything that is possible in Excel (formattings, formulas etc.). It yould be much more than just transforming XML to CSV.
Why do you want to change this? I can see that the resulting XML-Excel file usually is huge, is that the reason?
Now, since Excel 2007 format (xlsx) is basically a zip-archive of some XML-files describing the structure and the data of the file -- just rename the file extension name of any xlsx to zip and inspect after extracting -- you might be able to adapt your existing solution, i.e. instead of creating one SpreadsheetML-(XML)File create several and pack/zip them one the server. I assume your normal server installation should have the necessary tools.
BUT - this solution is difficult to maintain (as you might know wiht you current solution -- if I am at all right) and changes in the XSLT to add new functionality requires quite a bit of knowledge. So again I as well can recommend Aspose.Cells, even some knowledgeable users might be able to change simple formats.
HTH
Andreas
If you don't have office 2003 *or later) DLLs referenced to the project, I'm afraid you can't read that Office XML data in your program directly, unless of course you can manually parse the whole XML by studying its format.
You can use Open XML SDK to create or read xlsx files.
http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=5124

c# read excel worksheet

Could someone help me read a simple excel worksheet in c# app? I'd like to be able to iterate each row and have a handle on each of the columns.
Thanks,
rod.
This one is the easiest method I have found:
Create Excel (.XLS and .XLSX) file from C#
The general method is to use Excel COM Interop. A quick google will find plenty of tutorials. Here's one for creating a sheet - it should point you in the direction (reading is pretty much the same).
An alternative method is to use ADO.Net. This is only really viable if your Excel sheet is well formed as a table ( ie. Database), but is easier than the interop approach.
Here is a sample using OLEDB
http://www.techiesweb.net/2009/12/reading-records-excel-file-insert-database-aspnet/
If you are going to open Excel 2007 or 2010 workbook (ooxml format), you can download Open XML SDK 2.0 for Microsoft Office (which doesn't require you to have MS office installed).
While Excel COM Interop works, it requires Excel to be installed on the client machine. If that isn't an issue then all good, but if it is you might consider looking at the Aspose.Cells library (no affiliation, just used them before). They're simple and powerful, although do carry a commercial license cost.
I've used ADO.NET and Jet in the past. Be warned that if you have columns that aren't obviously of one type you will see weird things happen. Jet tries to assign a datatype to a column based on the first several vales. The nice thing is that you can query the spreadsheet like it is a table.

Create Excel files from C# without office [duplicate]

This question already has answers here:
How do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office?
(47 answers)
Closed 4 years ago.
I am writing a program that generates excel reports, currently using the Microsoft.Interop.Excel reference. My dev computer has Excel on it, but the end user may or may not have Office installed. Will this tool fail if Office isn't installed on the end users computer, or is this interop service separate from the actual application?
If you're interested in making .xlsx (Office 2007 and beyond) files, you're in luck. Office 2007+ uses OpenXML which for lack of a more apt description is XML files inside of a zip named .xlsx
Take an excel file (2007+) and rename it to .zip, you can open it up and take a look. If you're using .NET 3.5 you can use the System.IO.Packaging library to manipulate the relationships & zipfile itself, and linq to xml to play with the xml (or just DOM if you're more comfortable).
Otherwise id reccomend DotNetZip, a powerfull library for manipulation of zipfiles.
OpenXMLDeveloper has lots of resources about OpenXML and you can find more there.
If you want .xls (2003 and below) you're going to have to look into 3rd party libraries or perhaps learn the file format yourself to achieve this without excel installed.
Unless you have Excel installed on the Server/PC or use an external tool (which is possible without using Excel Interop, see Create Excel (.XLS and .XLSX) file from C#), it will fail. Using the interop requires Excel to be installed.
Try EPPlus if you use Excel 2007. Supports ranges, cellstyling, charts, shapes, pictures and a lot of other stuff
There are a handful of options:
NPOI - Which is free and open
source.
Aspose - Is definitely
not free but robust.
Spreadsheet
ML - Basically XML for creating spreadsheets.
Using the Interop will require that the Excel be installed on the machine from which it is running. In a server side solution, this will be awful. Instead, you should use a tool like the ones above that lets you build an Excel file without Excel being installed.
If the user does not have Excel but has a tool that will read Excel (like Open Office), then obviously they will be able to open it. Microsoft has a free Excel viewer available for those users that do not have Excel.
An interop calls something else, it's an interoperability assembly, so you're inter-operating with something...in this case Excel, the actual installed Excel.
In this case yes, it will fail to run because it depends on excel, you're just calling excel functions. If they don't have it installed...out of luck.
There are methods to generate without Excel, provided the 2007 file format is ok, here's a few:
http://excelpackage.codeplex.com/
http://simpleooxml.codeplex.com/
as I said though, this is the 2007 format, normally if anything, that's the deal-breaker.
Use OleDB, you can create, read, and edit excel files pretty easily. Read the MSDN docs for more info:
http://msdn.microsoft.com/en-us/library/aa288452(VS.71).aspx
I've used OleDB to read from excel files and I know you can create them, but I haven't done it firsthand.
You could use the ExcelStorage Class of the FileHelpers library, it's very easy and simple... you will need Excel 2000 or later installed on the machine.
The FileHelpers is a free and easy to
use .NET library to import/export
data from fixed length or delimited
records in files, strings or streams.

What is the best practice to create a Excel 2007 Workbook

I want to know what is the best practice to create a Excel 2007 Workbook using C#, with its datasource being a raw flat file or a table in database.
You can use
"Open XML SDK 2.0 for Microsoft Office"
It's more comfortable than harcore manually hacking OpenXML spec. There are .NET strongly typed wrapper classes so it's not hard to create a simple sheet. You don't need any interop and msoffice installed and it's safe for server soluitions - there are only a few dlls which you can ship in your solution.
I did mail-merge solution and it wasn't so scary.
But as always, when it's possible, I'm prefering plain csv format.
I personally like creating CSV's, which can be opened directly in Excel. It's a lot less work than trying to hack the Office Open XML specification, and you don't need COM interop to Excel (which requires a copy of Excel to work).
You can use the Office Primary Interop Assemblies to completely automate Excel 2007, and create the workbook from within C#.
This gives you the most control, as you have complete control over how you map from DB or flat file -> Excel workbook/worksheet.
I am using
http://www.leniel.net/2009/07/creating-excel-spreadsheets-xls-xlsx-c.html
for creating excel . Seems good so far.

How can I programmatically create, read, write an excel without having office installed?

I'm confused as hell with all the bazillion ways to read/write/create excel files. VSTO, OLEDB, etc, but they all seem to have the requirement that office must be installed.
Here is my situation: I need to develop an app which will take an excel file as input, do some calculations and create a new excel file which will basically be a modification of the first excel file. All with the constraint that the machine that runs this may not have office installed. (Don't ask why...)
I need to support all excel formats. The only saving grace is that the formats spreadsheets themselves are really simple. Just a bunch of columns and values, nothing fancy. And unfortunately no CSV as the end user might not even know what a CSV file is.
write your excel in HTML table format:
<html>
<body>
<table>
<tr>
<td style="background-color:#acc3ff">Cell1</td>
<td style="font-weight:bold">Cell2</td>
</tr>
</table>
</body>
</html>
and give your file an xls extension. Excel will convert it automatically
Without Office installed you'll need something designed to understand the Excel binary file format (unless you only want to open Office 2007 .xlsx files).
The best I've found (and that I use) is SpreadsheetGear, which in addition to being .NET native, is much faster and more stable then the COM/OLE solutions (which I've used in the past)
read and write csv files instead. Excel reads them just fine and they're easier to use. If you need to work against .xls files then try having support for OpenOffice as well as Excel. OpenOffice can read and write excel files.
Did you consider way number bazillion and one: using the Open XML SDK? You can retain styles and tweak it to your liking. Anything you can do in an actual file is possible to achieve programatically. The SDK comes with a tool called Document Reflector that shows the underlying XML and even shows LINQ statements that can be used to generate them. That is key to playing around with it, seeing how the changes are made, then recreating that in code.
The only caveat is this will work for the new XML based formats (*.xlsx) not the older versions. There's a slight learning curve but more material is making its way on blogs and other sites.
If cost is not an issue, I'd suggest looking in Aspose's Excel product. I use their Word product and I've been satisfied.
Aspose.Cells
Excel XLSX files "just" XML files - more precisely ZIP files containing several XML files. Just rename a Excel file Test.xslx to Test.zip and open it with your favourit ZIP program. XML schemas are, afaik, standardized and availiable. But I think it might not be that easy to manipulate them only using primitive XML processiing tools and frameworks.
Excel files are in a proprietary format so (afaik) you're not going to be able to do this without having the office interop available. Some third party tools exist (which presumably licence the format from MS?) but I've not used them myself to comment on their usefulness.
I assume that you can't control the base file format, i.e. simple CSV or XML formats aren't going to be possible?
I used to use a very nice library called CarlosAg, which uses Excel XML format. It was great (and Excel recognizes the format), and also incredibly fast. Check it out here.
Oh, as a side note, we used to use this for the very same reason you need it. The servers that generated these files were not able to have Excel installed.
If you cannot work with CSV files as per #RHicke's suggestion, and assuming you are working on a web app, since a desktop app would be guaranteed to have XL installed as per requirements.
I'd say, create your processing app as a webservice, and build an XL addin which will interact with your webservice directly from XL.
For XLSX files, look at using http://www.codeplex.com/ExcelPackage. Otherwise, some paid 3rd party solutions are out there, like the one David suggested.
I can understand the requirement of not having office installed on a server machine.
There are many libraries like aspose being available, some of them requiring license though.
If you are targeting MS Excel formats, then a native, Interoperability library, ACE OLEDB data provider, from Microsoft is available which you can install on a machine and start reading, writing programmatically. You need to define a connection string and commands as per you needs. (Ref: This article #yoursandmyideas)talks about using this library along with setup and troubleshooting information.

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