try
            {
                panel1.Visible = true;
                //模拟输入
                HtmlElement element1 = webBrowser1.Document.GetElementById("ctl00_Main_kw");
                element1.InnerText = textBox29.Text;
                //模拟点击
                HtmlElement formLogin = webBrowser1.Document.Forms["form1"];
                formLogin.InvokeMember("submit");
            }
            catch (Exception ex)
            {
                MessageBox.Show("错误描述："+ex);
            }

          C#中的模拟输入与提交跟DELPHI中的代码类似，顺便把DELPHI的代码也贴出来~

语法都大同小异，贴出一段百度关键词查询的多线程代码，以备后用。

        //查询百度关键词排名多线程
        private void createBDKEYThreadThread()
        {

            WebHtml = "";
            PageNo = 1;         
            string key = (textBox8.Text);
            WebHtml = getHttp("http://www.baidu.com/s?wd=" + key,null); //获取源码

            for (int j = 0; j < 100; j++)
            {

                Regex r = new Regex(textBox3.Text);
                Match m = r.Match(WebHtml); // 在字符串中匹配网址           //等同于DELPHI的POS（）函数