[C#] Import Excel to GridView

이렇게 구현이 가능합니다. 
아래와 같이 간단하게 구현하여 데이터를 로드 한 이후 

using System;
using System.Data;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            System.Data.OleDb.OleDbConnection MyConnection;
            System.Data.DataSet DtSet;
            System.Data.OleDb.OleDbDataAdapter MyCommand;
            MyConnection = new System.Data.OleDb.OleDbConnection(@"provider=Microsoft.Jet.OLEDB.4.0;Data Source='c:\csharp.net-informations.xls';Extended Properties=Excel 8.0;");
            MyCommand = new System.Data.OleDb.OleDbDataAdapter("select * from [Sheet1$]", MyConnection);
            MyCommand.TableMappings.Add("Table", "Net-informations.com");
            DtSet = new System.Data.DataSet();
            MyCommand.Fill(DtSet);
            dataGridView1.DataSource = DtSet.Tables[0];
            MyConnection.Close();
        }
    }
}