测试可用:

private void SaveSnapshot_Click(object sender, EventArgs e)
        {
            this.webBrowser1.Navigate(txturl.Text);
 
            this.webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted);  // 增加网页加载完成事件处理函数
            this.webBrowser1.NewWindow += new CancelEventHandler(webBrowser_NewWindow);

        }

        void webBrowser_NewWindow(object sender,CancelEventArgs e) {

            string url=((WebBrowser)sender).StatusText;
            this.webBrowser1.Navigate(url);
            e.Cancel = true;
        }