以下代码连接本地数据库是正常的

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

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

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnectionStringBuilder scsb = new SqlConnectionStringBuilder();
            scsb.DataSource = @"localhost";
            scsb.IntegratedSecurity = true;
            scsb.InitialCatalog = "XA_IVR";

            SqlConnection myConnection = new SqlConnection(scsb.ConnectionString);
            myConnection.Open();
            if (myConnection.State == ConnectionState.Open)
            {
                MessageBox.Show(this,"连接成功","OK");
            }
            else
                MessageBox.Show(this,"连接失败","Failed");
            myConnection.Close();
        }
    }
}

如果数据库在远程比如10.2.20.20使用

scsb.DataSource = @"10.2.20.20:1433";

代替

scsb.DataSource = @"localhost";

为何连接会失败？

应该如何修改呢 谢谢