You can use a library called ExcelLibrary. It's a free, open source library posted on Google Code:
ExcelLibrary
This looks to be a port of the PHP ExcelWriter that you mentioned above. It will not write to the new .xlsx format yet, but they are working on adding that functionality in.
It's very simple, small and easy to use. Plus it has a DataSetHelper that lets you use DataSets and DataTables to easily work with Excel data.
ExcelLibrary seems to still only work for the older Excel format (.xls files), but may be adding support in the future for newer 2007/2010 formats.
You can also use EPPlus, which works only for Excel 2007/2010 format files (.xlsx files). There's also NPOI which works with both.
There are a few known bugs with each library as noted in the comments. In all, EPPlus seems to be the best choice as time goes on. It seems to be more actively updated and documented as well.
Also, as noted by @АртёмЦарионов below, EPPlus has support for Pivot Tables and ExcelLibrary may have some support (Pivot table issue in ExcelLibrary)
Here are a couple links for quick reference:
ExcelLibrary - GNU Lesser GPL
EPPlus - GNU (LGPL) - No longer maintained
EPPlus 5 - Polyform Noncommercial - Starting May 2020
NPOI - Apache License
Here some example code for ExcelLibrary:
Here is an example taking data from a database and creating a workbook from it. Note that the ExcelLibrary code is the single line at the bottom:
//Create the data set and table
DataSet ds = new DataSet("New_DataSet");
DataTable dt = new DataTable("New_DataTable");
//Set the locale for each
ds.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
dt.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
//Open a DB connection (in this example with OleDB)
OleDbConnection con = new OleDbConnection(dbConnectionString);
con.Open();
//Create a query and fill the data table with the data from the DB
string sql = "SELECT Whatever FROM MyDBTable;";
OleDbCommand cmd = new OleDbCommand(sql, con);
OleDbDataAdapter adptr = new OleDbDataAdapter();
adptr.SelectCommand = cmd;
adptr.Fill(dt);
con.Close();
//Add the table to the data set
ds.Tables.Add(dt);
//Here's the easy part. Create the Excel worksheet from the data set
ExcelLibrary.DataSetHelper.CreateWorkbook("MyExcelFile.xls", ds);
Creating the Excel file is as easy as that. You can also manually create Excel files, but the above functionality is what really impressed me.
If you don’t want to look for a solution, but just want to solve the problem, insert this key in your registry to suppress the notification:
[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Security]
“ExtensionHardening”=dword:00000000
You can accomplish the above by doing the following:
- Open your Registry (Start -> Run -> regedit.exe)
- Navigate to HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\OFFICE\12.0\EXCEL\SECURITY
- Right click in the right window and choose New -> DWORD
- Type “ExtensionHardening” as the name (without the quotes)
- Verify that the data has the value “0″
Best Answer
Try calling the file
blah.xlsx
instead ofblah.xls
. Excel apparently wants XML files to have an "xlsx" extension. The "xls" extension is for the binary format files.Edit in response to your comment:
I was wrong:
xlsx
files aren't just the XML files, they're zip archives containing the XML format plus other metadata. All in all, it's a little complex to set up. I'd try renaming the file toblah.xml
, and see if that works. Otherwise I'm afraid you might have to look at how to make these zip files. There are two options:xlsx
files above what part 2 says you need, so read part 2 first, then part 1.