C#讀取host文件代碼

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

namespace 讀取host文件
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

    private void button1_Click(object sender, EventArgs e)
    {
        string str;
        StreamReader sr = new StreamReader(@"C:\windows\system32\drivers\etc" + "\\hosts", false);
        str = sr.ReadToEnd().ToString();
        sr.Close();
        this.richTextBox1.Text = str;///讀取

    }


}
}
@"C:\windows\system32\drivers\etc" + "\hosts"文件路徑</pre>