利用WebClient实现自动添写、提交表单

1。要提交的表单是：http://stock.business.sohu.com/q/hp.php；
表单要填写的内容保括：股票代码，时间范围
2。网页的源代码分析
这是我们要填写表单的内容：
 <form name=form_table method=post action=/q/hp.php OnSubmit="return checkvalue()">
 <td align=left valign=middle width=150 bgcolor=white>
  股票代码&nbsp;<INPUT size=6name=code value=600018>
  <input type=submit value='提交' id=submit name=submit>
  </td><td bgcolor=white valign=middle align=center width=250>
  开始日期&nbsp;<INPUT NAME=start_year VALUE=2004 SIZE=4 MAXLENGTH=4>&nbsp;年
  <SELECT NAME=start_month>
 <OPTION value=01>一月
<OPTION value=02>二月
<OPTION value=03>三月
<OPTION value=04>四月
<OPTION value=05>五月
<OPTION value=06 selected>六月
<OPTION value=07>七月
<OPTION value=08>八月
<OPTION value=09>九月
<OPTION value=10>十月
<OPTION value=11>十一月
<OPTION value=12>十二月
      </SELECT>&nbsp;月
  <INPUT NAME=start_day VALUE=28 SIZE=2 MAXLENGTH=2>&nbsp;日<br>
  结束日期&nbsp;<INPUT NAME=end_year VALUE=2005 SIZE=4 MAXLENGTH=4>&nbsp;年
  <SELECT NAME=end_month>
 <OPTION value=01>一月
<OPTION value=02>二月
<OPTION value=03>三月
<OPTION value=04>四月
<OPTION value=05>五月
<OPTION value=06>六月
<OPTION value=07 selected>七月
<OPTION value=08>八月
<OPTION value=09>九月
<OPTION value=10>十月
<OPTION value=11>十一月
<OPTION value=12>十二月
      </SELECT>&nbsp;月
  <INPUT NAME=end_day VALUE=28 SIZE=2 MAXLENGTH=2>&nbsp;日</td><td bgcolor=white valign=middle align=center>
 <input type=radio name=ss value=d  checked >交易日<br>
 <input type=radio name=ss value=w  >交易周<br>
 <input type=radio name=ss value=m  >交易月
 </td><td bgcolor=white valign=middle align=center>注: 所选记录请<br>不要超出300条。</td></tr>
  </FORM>
第一行告诉我们这个表单的action地址和发送方式，我们还可以得到股票代码，和日期的变量名称。下面我们就可以利用WebClient的UploadDate发送表单了。
public byte[] UploadData(
   string address,
   string method,
   byte[] data
);
代码如下：

            string uriString = "http://stock.business.sohu.com/q/hp.php";
            // 创建一个新的 WebClient 实例.
            WebClient myWebClient = new WebClient();
            string postData = "code=";
            postData+=textBox1.Text;
            postData+="&start_year=";
            postData+=dateTimePicker1.Value.Year.ToString();
            postData+="&start_month=";
            if(dateTimePicker1.Value.Month<10)
            {
                string str1="0"+dateTimePicker1.Value.Month.ToString();
                postData+="0"+dateTimePicker1.Value.Month.ToString();
            }
            else
            {
                postData+=dateTimePicker1.Value.Month.ToString();
            }
            postData+="&end_year=";
            postData+=dateTimePicker2.Value.Year.ToString();
            postData+="&end_month=";
            if(dateTimePicker2.Value.Month<10)
            {
                postData+="0"+dateTimePicker2.Value.Month.ToString();

            }
            else
            {
                postData+=dateTimePicker2.Value.Month.ToString();
            }
            postData+="&start_day=";
            if(dateTimePicker1.Value.Day<10)
            {
                postData+="0"+dateTimePicker1.Value.Day.ToString();
            }
            else
            {
                postData+=dateTimePicker1.Value.Day.ToString();
            }
            postData+="&end_day=";
            if(dateTimePicker2.Value.Day<10)
            {
                postData+="0"+dateTimePicker2.Value.Day.ToString();

            }
            else
            {
                postData+=dateTimePicker2.Value.Day.ToString();
            }
            //    02&end_year=2004&end_month=12&start_day=01&end_day=28";
            // 注意这种拼字符串的ContentType
            myWebClient.Headers.Add("Content-Type","application/x-www-form-urlencoded");
            // 转化成二进制数组
            byte[] byteArray = Encoding.ASCII.GetBytes(postData);
            // 上传数据，并获取返回的二进制数据.
            byte[] responseArray = myWebClient.UploadData(uriString,"POST",byteArray);
            srcCode=Encoding.ASCII.GetString(responseArray);
            int pos=0;
            if((pos=srcCode.IndexOf("<br><br><br><center>"))!=-1)
            {
                MessageBox.Show("您输入的股票代码不存在");
                return;

            }
            AnsCode(srcCode); srcCode是获得提交后的网页源代码，AnsCode是处理这些代码，以提取股票的各种数据放入数据库