Using templates in excel with C# - c#

As part of the c# program that I am producing I need to generate 1 workbook containing; 2 different worksheets and a 3rd that could be produced any number of times, what is the most effective way of doing this? I have looked into using templates although I am unsure how to repeat certain worksheets whilst only displaying others once. Any help or advice would be appreciated.

A simple way is to make a hands off template example workbook with the three worksheets. Then make a copy of it. Open both and re-copy worksheet number 3 on to the working workbook as a new worksheet as needed.
In response to the comment:
There are a couple of excel engines in a .net component products our there like spreadsheet gear or aspose cells. But if your application is a windows form based and where the application is guaranteed to run has office you can use office automation. You can't legally use office automation on a web server, but it is just as possible on a web server as on a client desktop. I've used the aspose cells and it's very easy to work with and very capable and a little less expensive than spreadsheet gear, but spreadsheet gear does also have a good reputation. Both of those components have very good documentation on how to do anything with excel. But if you have excel and want to use office automation, be sure to look for example code on the web on how to properly close excel from c# or vb.net. There are some tricks to getting it to close properly.

SpreadsheetGear for .NET has ISheet.CopyAfter / CopyBefore methods which enable you to copy an entire worksheet within a workbook or between workbooks.
You can see an example of duplicating a single worksheet multiple times in the Worksheet with Chart to Multiple Worksheets with Charts sample on the SpreadsheetGear / Excel Reporting Samples page here.
Disclaimer: I own SpreadsheetGear LLC

I have done this before with templates. I would create a template xls with the first two worksheets that you don’t want changed, then add a 3rd worksheet that you could copy to the end of the workbook (as you need more worksheets).
If you know ahead of time how many of the 3rd worksheet you need, then you can copy them to the end and delete the template 3rd slot.
ExcelTemplateManager t = new ExcelTemplateManager(template_path, log_path);
t.CopyWorksheetToEnd(3);
t.CopyWorksheetToEnd(3);
t.RemoveAtIndexWorksheet(3);
t.SetSomeValue(3);
t.SetSomeValue(4);
t.Close();
If you don’t know, then keep the template around to copy it to the end as needed, then when you are done, just remove the 3rd worksheet template.
ExcelTemplateManager t = new ExcelTemplateManager(template_path, log_path);
t.CopyWorksheetToEnd(3);
t.SetSomeValue(4);
t.CopyWorksheetToEnd(3);
t.SetSomeValue(5);
t.RemoveAtIndexWorksheet(3);
t.Close();
I used the Microsoft.Office.Interop.Excel dll to create my ExcelTemplateManger class. The basic idea is to create a copy of the template excel file, and work off the copy. Let me know if you need help setting that part up, but it should be too bad.

Related

Which is the best way to manipulate data/sheet of an excel document in C#

I'm currently busy with a task that involves both manipulating data in an excising excel document as well as the sheet itself.
In the past I've always used OleDbConnection and OleDbCommand to work with excel, but I've been reading about something called a Workbook and I'm not sure which way I should go about this.
Some examples of what I need to do include-
Inserting a new column
Deleting old columns
Setting a cell a certain colour depending on it's contents
Looking for duplicates and deleting them.
In your option which way would be the most efficient way to go about this.
Thanks
Best way would be to go with excel interop if you don't want to use any third party library.
Interop works and any action can be performed which you have mentioned in your question.
Refer this link for more info: http://csharp.net-informations.com/excel/csharp-excel-tutorial.htm
PS: above link is for c# and for interop to work ms excel must be installed on the system, this can be implemented in vb.net as well.
Hope this helps.
I have used Visual Studio Tools for Office, you will have workbooks, worksheets, columns, ranges, etc. Easy to manipulate using C#.
https://msdn.microsoft.com/en-us/library/bb608603.aspx
Install this package into your project Further no need to install Excel also this is fast mothod https://www.nuget.org/packages/ExcelDataReader/

Writing on open Excel application using NPOI

folks,
Environment
Windows 8.1
Visual Studio 2013
C#
Issue
How do I write values and make charts on visible Excel sheets using NPOI (https://npoi.codeplex.com/).
Why do I want that?
I'm developing an application to measure temperature in an apparatus. To put together experimental data in one place, I'd like to record data on an Excel sheet and make a chart on the sheet. In addition, I'd like to keep the Excel sheet visible and check the chart updated in real time.
You could also make graphs on Windows Form apps with MeasurementStudio by NationalInstruments for example but considering the flexibility of Excel charts (size and xy range changeable, easy-to-use user interface, etc...), I'd like to stick to Excel.
You can easily do this with Microsoft.Office.Interop.Excel by
ExcelApp.visible = true;. However, this module requires users to release every COM object generated. Otherwise, the objects remain and eat up memory. This is the reason I prefer to use NPOI.
How can I achieve this? Any answers would be appreciated.
You cannot do this with NPOI. NPOI reads and writes data from serialized Excel files. You cannot access those files while Excel has them open, and even if you could, Excel simply wouldn't re-read the files so your modifications wouldn't show up.
The problem you describe comes down to "I want to interact with a running Excel instance without using Excel interop". That's not going to work.

Loading Libraries to Excel Through Windows Form C#

This is my first question and I'm horribly scared my answer could already be on some other post. But I've searched for hours and I really can't get my head around it.
So here's the thing.
I'm working on a windows form that, very simplistically, has to open certain workbooks and run macros inside these workbooks.
The macros in these workbooks use certain functions that do not belong to standard excel libraries. I work in a bank and we have some proprietary functions and add-ins which are loaded every time we open certain exe files.
I can launch an excel application through:
Microsoft.Office.Interop.Excel.Application xlApp =
new Microsoft.Office.Interop.Excel.Application();
but this calls the normal excel. How can I add the libraries I need in this specific instance of excel?
The alternative solution is to launch excel with the libraries manually, using
System.Diagnostics.Process.Start("CMD.exe","My fancy excel");
but this takes a huge amount of time, as a new instance has to be created for each workbook.
Any thoughts or clarifications needed?
Thank you all for your time, hope I was clear enough!
When starting Excel through automation, it won't load any add-ins. So you have to explicitly load the add-ins using:
Application.RegisterXLL (for .xll add-ins), or
AddIns.Add / AddIn.Installed = true (for .xla or .xlam add-ins).
Here is an older question on the topic: Loading addins when Excel is instantiated programmatically, and a related MSDN blog post: http://blogs.msdn.com/b/accelerating_things/archive/2010/09/16/loading-excel-add-ins-at-runtime.aspx and another Microsoft support article: https://support.microsoft.com/en-us/kb/213489.

Need to convert Excel sheets into Text (tab delimited ) as in MS Excel 2007 programatically using C#

Ok, here is the problem
MS Excel allows me to save the whole sheet as text tab delimited
I'm using this text in a program , but the user needs to make the previous step manually
I want to automate this step so the user only import the Excel Book into my program , and shows how many sheets inside it letting the user select the desired sheet and then the program will convert this sheet into text (tab delimited ) , any ideas ?
Well... one of the easiest to learn methods would be the use Excel Interop. The downside of this method is it (1.) requires Excel to be installed and (2.) Can get messy very quickly... but generally it makes sense.
I suggest familiarizing yourself with Excel Interop. Now, take note of the SaveAs method for the Workbook object.
Loop through the Worksheets property of the opened Workbook.
Display the sheet names for the user to choose.
Get the desired sheet by name and access the Worksheet object
Use the desired Worksheet's Select method
Use the Workbook's SaveAs method. Be sure to use FileFormat option to make it tab delimited.
Hope that helps. Just remember, it's doable.
There are several options:
OpenXML 2.0 from MS - http://msdn.microsoft.com/en-us/library/bb448854.aspx...
It is a free library that does NOT require office to be installed... you can read + write Office files including Excel and Word (Version 2007 and up...).
VSTO/Office Interop from MS - http://msdn.microsoft.com/en-US/office/hh128771.aspx
this need Office to be installed and works only in desktop apps (NOT services or ASP.NET..) and let's you automate whatever you want...

Open a single worksheet (single tab) from a huge excel file on a web browser using c# asp.net / MVC

I have huge excel files that I have to open from web browser. It takes several minutes to load huge file. Is it possible to open a single worksheet (single tab) at a time from excel file that contains many worksheets? I have to do this using C# / asp.net MVC
I'm assuming you have the excel workbook on the server and just want to send a single worksheet to the client. Does the user then edit the worksheet? Will they be uploading it back?
Assuming this is just a report then why not use the OpenXML sdk to read the workbook, extrac the sheet in question and send it back to the client? This is what #Jim in the comments was suggesting. You can get the SDK here: Open XML SDK 2.0 for Microsoft Office . However, I'm not sure if it will work with the 'old' excel format. I assume you'll need to save the template workbook in the new Office formats (xslx).
Your question is slightly unclear as to where the spreadsheet is stored.
If it's on a server you control, process it, extracting sheets you need, and create other sheets which are smaller in size. (Or possibly save them in a different format.).
If they're not on a server you control, download the file using C#, then go through a similiar process of extracting the sheet before opening it.
Having said that, I've dealt with some largish spreadsheets (20MB or so), and haven't really had a problem processing the entire spreadsheet as a whole.
So where is the bottleneck? Your network or possibly the machine you're running?
Use third party components.
We are fighting with server side Excel generation for years and has been defeated.
We bought third party components and all problems gone.
From your question, it seems you want to improve load time by using (opening) the data from one worksheet instead of the whole workbook. If this is the case and you only want the data, then access the workbook using ADO.NET with OLEDB provider. (You can use threading to load each worksheet to improve load performance. For instance, loading three large data sets in three worksheets took 17 seconds. Loading each worksheet on a separate thread, loaded same data sets in 5 seconds.)
From experience, performance starts to really suffer with workbooks of 40MB or more. Especially, if workbooks contain many formulas. My largest workbook of 120MB takes several minutes to load. Using OLEDB access, I can load, access, and process the same data in a few seconds.
If you want the client to open data in Excel, gather data via ADO.NET/OLEDB, get XML and transform into XMLSS using Xslt. Which is easy and there is much documentation and samples.
If you just want to present the data, gather data via ADO.NET/OLEDB, get XML and transform into HTML using Xslt. Which is easy and there is much documentation and samples.
Be aware that the browser and computer become non-responsive with large data sets. I had to set limit upper limit. If limit was reaced, I notified user of truncated results, otherwise, user thought computer was "locked".
Take a look at this question in StackOverflow:
Create Excel (.XLS and .XLSX) file from C#
I think you can open your workbook on the server (inside your ASP.NET MVC application) and process only the specific worksheet you want. You can then send such worksheet to the user using NPOI.
The following post shows you how to do that using an ASP.NET MVC application:
Creating Excel spreadsheets .XLS and .XLSX in C#
You can't "say" to Excel, even via Interop that you only want a single worksheet. There are a lot of explanations, like formulas, references and links between them, which makes the task impossible.
If you only want to read the data from the worksheet, maybe OLEDB Data Provider is the best option for you. Here is a full example: Reading excel file using OLEDB Data Provider
Otherwise, you will need to load the entire workbook in memory before do anything with it.

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