Reading Excel files from C#

Question

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.

Answer 1

We use ClosedXML in rather large systems.

• Free
• Easy to install
• Straight forward coding
• Very responsive support
• Developer team is extremly open to new suggestions. Often new features and bug fixes are implemented within the same week

Answer 2

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

Answer 3

SmartXLS is another excel spreadsheet component which support most features of excel Charts,formulas engines, and can read/write the excel2007 openxml format.

Answer 4

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;
        }
    }
}

Answer 5

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)

Answer 6

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.