StreamReader in class for SqlConnection

我在课堂上有这段代码，应该从文本框中读取4行，但程序停止了，所以我不知道错误在哪里

using System.Data.SqlClient;
using System.IO;
namespace tours
{
   class myConnection
   {
       public static SqlConnection GetConnection()
       {
            string path = "C:''Users''marek''Documents''Visual Studio 2012''Projects''tours''tours''sql_string.txt";
            StreamReader sr = new StreamReader(File.Open(path, FileMode.Open));
            while (sr.Peek() >= 0)
            {
            }
            string str = "Data Source='" + sr.ReadLine() + "';Initial Catalog ='" + sr.ReadLine() + "' ;user='" + sr.ReadLine() + "';password= '" + sr.ReadLine() + "'";
            SqlConnection con = new SqlConnection(str);
            con.Open();
            return con;
       }
    }
}

这就是我在形式中的称呼

private void nastaveni_Load(object sender, EventArgs e)
{
        try
        {
            nacti_spojeni();
            myConnection.GetConnection();
        }
        catch (Exception ex)
        {
            MessageBox.Show("" + ex);
        }
}

//while (sr.Peek() >= 0)
//{
//}
string str = "Data Source='" + sr.ReadLine() + "';Initial Catalog ='" + sr.ReadLine() + "' ;user='" + sr.ReadLine() + "';password= '" + sr.ReadLine() + "'";

var lines =  File.ReadAllLines(path);
if (lines.Length >=4)
{
    string str = string.Format("Data Source='{0}';Initial Catalog ='{1}' ;user='{2}';password= '{3}'"
        , lines[0], lines[1], lines[2], lines[3]);
}