Form1.cs

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 WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Gecko.Xpcom.Initialize(Application.StartupPath+ "\\xulrunner");
            geckoWebBrowser1.Navigate("https://www.google.com");
        }

        //hien thi tittle cua web

        private void Form1_Load(object sender, EventArgs e)
        {
            geckoWebBrowser1.Navigate("https://www.google.com");
            geckoWebBrowser1.DocumentCompleted += GeckoWebBrowser1_DocumentCompleted;
        }

        private void GeckoWebBrowser1_DocumentCompleted(object sender, Gecko.Events.GeckoDocumentCompletedEventArgs e)
        {
            tabControl1.SelectedTab.Text = geckoWebBrowser1.DocumentTitle;
        }



        //bieu tuong kinh lup
        private void toolStripButton5_Click(object sender, EventArgs e)
        {
            geckoWebBrowser1.Navigate("https://www.google.com");
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            
            
                web.Navigate(txtUrl.Text);
            
        }
        //nut tao newtab
        Gecko.GeckoWebBrowser webTab = null;
        private void btnNewtab_Click(object sender, EventArgs e)
        {
            TabPage tab = new TabPage();
            tab.Text = "New Tab";
            tabControl1.Controls.Add(tab);
            tabControl1.SelectTab(tabControl1.TabCount - 1);
            webTab = new Gecko.GeckoWebBrowser();
            webTab.Parent = tab;
            webTab.Dock = DockStyle.Fill;
            webTab.Navigate("https://www.google.com");
            txtUrl.Text= "https://www.google.com";
            webTab.DocumentCompleted += WebTab_DocumentCompleted1;
        }

        private void WebTab_DocumentCompleted1(object sender, Gecko.Events.GeckoDocumentCompletedEventArgs e)
        {
            tabControl1.SelectedTab.Text = webTab.DocumentTitle;
        }

        
//nut go back
        private void toolStripButton2_Click(object sender, EventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            if (web != null)
            {
                if (web.CanGoBack)
                    web.GoBack();
            }
        }
//nut go forward
        private void toolStripButton3_Click(object sender, EventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            if (web != null)
            {
                if (web.CanGoForward)
                    web.GoForward();
            }

        }
//nhap url vao textbox cua cac tab
        private void txtUrl_KeyDown(object sender, KeyEventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            
            
                if(e.KeyCode==Keys.Enter)
                { web.Navigate(txtUrl.Text); }
            
        }
//nut home
        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
           if(web!=null)
            {
                web.Navigate("https://www.google.com");
            }
        }
//nut refresh
        private void toolStripButton6_Click(object sender, EventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            if (web != null)
            {
                web.Refresh();
            }
        }
//nut stop
        private void toolStripButton4_Click(object sender, EventArgs e)
        {
            Gecko.GeckoWebBrowser web = tabControl1.SelectedTab.Controls[0] as Gecko.GeckoWebBrowser;
            if (web != null)
            {
                web.Stop();
            }
        }
//nut close-all-tab
        private void button1_Click(object sender, EventArgs e)
        {
            //

        }

        

    }
}