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Is there a free or open source library to read Excel files (.xls) directly from a C# program?
It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I've been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I'd like to eliminate the manual step.
var fileName = string.Format("{0}\\fileNameHere", Directory.GetCurrentDirectory());
var connectionString = string.Format("Provider=Microsoft.Jet.OLEDB.4.0; data source={0}; Extended Properties=Excel 8.0;", fileName);
var adapter = new OleDbDataAdapter("SELECT * FROM [workSheetNameHere$]", connectionString);
var ds = new DataSet();
adapter.Fill(ds, "anyNameHere");
DataTable data = ds.Tables["anyNameHere"];
This is what I usually use. It is a little different because I usually stick a AsEnumerable() at the edit of the tables:
var data = ds.Tables["anyNameHere"].AsEnumerable();
as this lets me use LINQ to search and build structs from the fields.
var query = data.Where(x => x.Field<string>("phoneNumber") != string.Empty).Select(x =>
new MyContact
{
firstName= x.Field<string>("First Name"),
lastName = x.Field<string>("Last Name"),
phoneNumber =x.Field<string>("Phone Number"),
});
If it is just simple data contained in the Excel file you can read the data via ADO.NET. See the connection strings listed here:
http://www.connectionstrings.com/?carrier=excel2007 or http://www.connectionstrings.com/?carrier=excel
-Ryan
Update: then you can just read the worksheet via something like select * from [Sheet1$]
The ADO.NET approach is quick and easy, but it has a few quirks which you should be aware of, especially regarding how DataTypes are handled.
This excellent article will help you avoid some common pitfalls: http://blog.lab49.com/archives/196
This is what I used for Excel 2003:
Dictionary<string, string> props = new Dictionary<string, string>();
props["Provider"] = "Microsoft.Jet.OLEDB.4.0";
props["Data Source"] = repFile;
props["Extended Properties"] = "Excel 8.0";
StringBuilder sb = new StringBuilder();
foreach (KeyValuePair<string, string> prop in props)
{
sb.Append(prop.Key);
sb.Append('=');
sb.Append(prop.Value);
sb.Append(';');
}
string properties = sb.ToString();
using (OleDbConnection conn = new OleDbConnection(properties))
{
conn.Open();
DataSet ds = new DataSet();
string columns = String.Join(",", columnNames.ToArray());
using (OleDbDataAdapter da = new OleDbDataAdapter(
"SELECT " + columns + " FROM [" + worksheet + "$]", conn))
{
DataTable dt = new DataTable(tableName);
da.Fill(dt);
ds.Tables.Add(dt);
}
}
Here's some code I wrote in C# using .NET 1.1 a few years ago. Not sure if this would be exactly what you need (and may not be my best code :)).
using System;
using System.Data;
using System.Data.OleDb;
namespace ExportExcelToAccess
{
/// <summary>
/// Summary description for ExcelHelper.
/// </summary>
public sealed class ExcelHelper
{
private const string CONNECTION_STRING = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=<FILENAME>;Extended Properties=\"Excel 8.0;HDR=Yes;\";";
public static DataTable GetDataTableFromExcelFile(string fullFileName, ref string sheetName)
{
OleDbConnection objConnection = new OleDbConnection();
objConnection = new OleDbConnection(CONNECTION_STRING.Replace("<FILENAME>", fullFileName));
DataSet dsImport = new DataSet();
try
{
objConnection.Open();
DataTable dtSchema = objConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
if( (null == dtSchema) || ( dtSchema.Rows.Count <= 0 ) )
{
//raise exception if needed
}
if( (null != sheetName) && (0 != sheetName.Length))
{
if( !CheckIfSheetNameExists(sheetName, dtSchema) )
{
//raise exception if needed
}
}
else
{
//Reading the first sheet name from the Excel file.
sheetName = dtSchema.Rows[0]["TABLE_NAME"].ToString();
}
new OleDbDataAdapter("SELECT * FROM [" + sheetName + "]", objConnection ).Fill(dsImport);
}
catch (Exception)
{
//raise exception if needed
}
finally
{
// Clean up.
if(objConnection != null)
{
objConnection.Close();
objConnection.Dispose();
}
}
return dsImport.Tables[0];
#region Commented code for importing data from CSV file.
// string strConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" +"Data Source=" + System.IO.Path.GetDirectoryName(fullFileName) +";" +"Extended Properties=\"Text;HDR=YES;FMT=Delimited\"";
//
// System.Data.OleDb.OleDbConnection conText = new System.Data.OleDb.OleDbConnection(strConnectionString);
// new System.Data.OleDb.OleDbDataAdapter("SELECT * FROM " + System.IO.Path.GetFileName(fullFileName).Replace(".", "#"), conText).Fill(dsImport);
// return dsImport.Tables[0];
#endregion
}
/// <summary>
/// This method checks if the user entered sheetName exists in the Schema Table
/// </summary>
/// <param name="sheetName">Sheet name to be verified</param>
/// <param name="dtSchema">schema table </param>
private static bool CheckIfSheetNameExists(string sheetName, DataTable dtSchema)
{
foreach(DataRow dataRow in dtSchema.Rows)
{
if( sheetName == dataRow["TABLE_NAME"].ToString() )
{
return true;
}
}
return false;
}
}
}
While you did specifically ask for .xls, implying the older file formats, for the OpenXML formats (e.g. xlsx) I highly recommend the OpenXML SDK (http://msdn.microsoft.com/en-us/library/bb448854.aspx)
I did a lot of reading from Excel files in C# a while ago, and we used two approaches:
The latter approach was much faster: reading a big table with 20 columns and 200 lines would take 30 seconds via COM, and half a second via ODBC. So I would recommend the database approach if all you need is the data.
Cheers,
Carl
ExcelMapper is an open source tool (http://code.google.com/p/excelmapper/) that can be used to read Excel worksheets as Strongly Typed Objects. It supports both xls and xlsx formats.
I want to show a simple method to read xls/xlsx file with .NET. I hope that the following will be helpful for you.
private DataTable ReadExcelToTable(string path)
{
//Connection String
string connstring = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties='Excel 8.0;HDR=NO;IMEX=1';";
//the same name
//string connstring = Provider=Microsoft.JET.OLEDB.4.0;Data Source=" + path + //";Extended Properties='Excel 8.0;HDR=NO;IMEX=1';";
using(OleDbConnection conn = new OleDbConnection(connstring))
{
conn.Open();
//Get All Sheets Name
DataTable sheetsName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,new object[]{null,null,null,"Table"});
//Get the First Sheet Name
string firstSheetName = sheetsName.Rows[0][2].ToString();
//Query String
string sql = string.Format("SELECT * FROM [{0}]",firstSheetName);
OleDbDataAdapter ada =new OleDbDataAdapter(sql,connstring);
DataSet set = new DataSet();
ada.Fill(set);
return set.Tables[0];
}
}
Code is from article: http://www.c-sharpcorner.com/uploadfile/d2dcfc/read-excel-file-with-net/. You can get more details from it.
Not free, but with the latest Office there's a very nice automation .Net API. (there has been an API for a long while but was nasty COM) You can do everything you want / need in code all while the Office app remains a hidden background process.
Lately, partly to get better at LINQ.... I've been using Excel's automation API to save the file as XML Spreadsheet and then get process that file using LINQ to XML.
SpreadsheetGear for .NET is an Excel compatible spreadsheet component for .NET. You can see what our customers say about performance on the right hand side of our product page. You can try it yourself with the free, fully-functional evaluation.
I recommend the FileHelpers Library which is a free and easy to use .NET library to import/export data from EXCEL, fixed length or delimited records in files, strings or streams + More.
The Excel Data Link Documentation Section http://filehelpers.sourceforge.net/example_exceldatalink.html
You can try using this open source solution that makes dealing with Excel a lot more cleaner.
you could write an excel spreadsheet that loads a given excel spreadsheet and saves it as csv (rather than doing it manually).
then you could automate that from c#.
and once its in csv, the c# program can grok that.
(also, if someone asks you to program in excel, it's best to pretend you don't know how)
(edit: ah yes, rob and ryan are both right)
I know that people have been making an Excel "extension" for this purpose.
You more or less make a button in Excel that says "Export to Program X", and then export and send off the data in a format the program can read.
http://msdn.microsoft.com/en-us/library/ms186213.aspx should be a good place to start.
Good luck
Just did a quick demo project that required managing some excel files. The .NET component from GemBox software was adequate for my needs. It has a free version with a few limitations.
Excel Data Reader is the way to go!
It´s Open Source, at http://exceldatareader.codeplex.com/ and actively developed.
We been using it for reading Tabular (and sometimes not so tabular) worksheets for a couple of years now (In a financial application).
Works like a charm to read unit test data from human-readable sheets.
Just avoid the feature of trying to return DateTime's, as, for Excel, DateTime's are just double numbers.