How can read text file in c#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;

namespace WindowsFormsApplication1
{
    public partial class Form3 : Form
    {
        public Form3()
        {
            InitializeComponent();
        }

        private void Form3_Load(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();

            // put each line of the text file into a string array. 
            string[] lines = System.IO.File.ReadAllLines(@"c:\sample.txt");

            // loop thru each line
            for (int i = 0; i < lines.Length; i++)
            {
                DataRow newrow = dt.NewRow();

                // split each line into words by spaces
                string[] words = lines[i].Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

                // if i = 0, means this is the header row
                if (i == 0)
                {
                    for (int j = 0; j < words.Length; j++)
                    {
                        // add column
                        dt.Columns.Add(words[j]);

                    }
                }
                else
                {
                    for (int j = 0; j < words.Length; j++)
                    {
                        // fill cell content
                        newrow[dt.Columns[j]] = words[j];
                    }

                    // add new row
                    dt.Rows.Add(newrow);
                }
            }

            dataGridView1.DataSource = dt;
        }
    }
}

string Data = File.ReadAllText(@"Path");