c#: WebBrowser控件html代码注入及交互

    [ComVisible(true)]
    public partial class Main : Form
    {
        public Main()
        {
            InitializeComponent();

            browser.ObjectForScripting = this;
        }

        private void txtUrl_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
                btnGo.PerformClick();
        }

        private void btnGo_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(txtUrl.Text))
                browser.Navigate(txtUrl.Text);
        }

        public void ShowURL(string url)
        {
            MessageBox.Show("OK, Url from website is:\r\n " + url, "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void browser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            if (browser.ReadyState == WebBrowserReadyState.Complete && e.Url == browser.Url)
            {
                //html注入
                var emt = browser.Document.GetElementById("watch-header");
                if (emt != null)
                {
                    Console.WriteLine("Yeah!");
                    //https://www.youtube.com/watch?v=vvppaufeD3Q
                    emt.OuterHtml = "<div align=‘right‘><a onclick=\"window.external.ShowURL(‘" + e.Url.ToString() + "‘);return false;\">Click Me!</a></div>\r\n" + emt.OuterHtml;
                }
            }
        }
    }