c#怎么获取网页上title的值

我想获取打开网站上的title的值“正式受理”，并将这个值写入Excel，应该怎么做，请各位大神赐教
图片说明

这是我写的代码

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

namespace MyAutoM
{
public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        //检测是否打开指定网页
        mshtml.HTMLDocument doc = getInternetExploer("http://135.64.132.8").Document;

        //获取title的值“正式受理”，请各位大神帮我补充一下

    }
     public static SHDocVw.InternetExplorer getInternetExploer(string url)
    {
        var shell = new Shell32.Shell();
        var windows = (SHDocVw.IShellWindows)shell.Windows();
        SHDocVw.InternetExplorer ie;
        foreach (object window in windows)
        {
            ie = window as SHDocVw.InternetExplorer;
            if (ie != null &&
                    string.Equals(System.IO.Path.GetFileName(ie.FullName),
                    "iexplore.exe", StringComparison.CurrentCultureIgnoreCase))
            {
                if (ie.LocationURL == url)
                {
                    return ie;
                }
            }
        }
        return null;
    }
}

}