使用webrequest或webclient登录winform

Question

从过去的几天开始，我一直在尝试使用webclient和webrequest登录，但出于某种原因，它无法正常工作。下面是我用来登录的代码。

private class CookieAwareWebClient : WebClient
{
    public CookieAwareWebClient()
        : this(new CookieContainer())
    { }
    public CookieAwareWebClient(CookieContainer c)
    {
        this.CookieContainer = c;
    }
    public CookieContainer CookieContainer { get; set; }

    protected override WebRequest GetWebRequest(Uri address)
    {
        WebRequest request = base.GetWebRequest(address);

        var castRequest = request as HttpWebRequest;
        if (castRequest != null)
        {
            castRequest.CookieContainer = this.CookieContainer;
        }

        return request;
    }
}

下面是发布的html表单：

<form method="post" action="">
    <div class="field">
        <label>Email Address:</label>
        <input type="text" value="" name="username">
        <div class="clear"></div>
    </div>

    <div class="field">
        <label>Password:</label>
        <input type="password" name="password">
        <div class="clear"></div>
    </div>

    <div class="field">
        <div style="float:left; width:102px;height:20px; display:block;">&nbsp;</div>

        <a class="button_forgot_password_blue" href="/my-account/forgotten-password"></a>
        <input type="submit" value="" class="button_login_blue" name="login">
        <div class="clear"></div>
    </div>
</form>  

正如您所看到的，动作块完全是空的，我如何登录this.please help。

更新：这是我想要做的代码。

private void button1_Click(object sender, EventArgs e)
        {

            using (var client = new CookieAwareWebClient())
            {
                var values = new NameValueCollection
              {
                    { "username", "vallue" },
                    { "password", "value" },
              };
                client.UploadValues("http://www.1stchoice.co.uk/my-account/sign-in", values);
                 // If the previous call succeeded we now have a valid authentication cookie
                // so we could download the protected page
                string result = client.DownloadString("http://www.1stchoice.co.uk/request/stop/7854140");
                File.WriteAllText(@"c:\temp\clc.txt", result);   
            }

        }