c#如何在文本框区域获取安全代码？

好了

 HtmlElementCollection bColl = webBrowser1.Document.GetElementsByTagName("span");
        foreach (HtmlElement bEl in bColl)
        {
            if (bEl.GetAttribute("style").Contains("Arial, sans-serif;font-size:14px;font-weight:bold;color:#2a2a2a"))
                txtLinkDetails.Text = bEl.OuterHtml.Split('"')[3];
        }

检查null通常需要检查元素是否为null，例如通过

！=空值

：）

问候

            Security code: <span style="font-family:'Segoe UI Bold', 'Segoe UI Semibold', 'Segoe UI', 'Helvetica Neue Medium', Arial, sans-serif;font-size:14px;font-weight:bold;color:#2a2a2a;">9949598</span>
        </td>

 HtmlElementCollection bColl = webBrowser1.Document.GetElementsByTagName("span");
        foreach (HtmlElement bEl in bColl)
        {
            if (bEl.GetAttribute("style").Contains("Arial, sans-serif;font-size:14px;font-weight:bold;color:#2a2a2a"))
                txtLinkDetails.Text = bEl.OuterHtml.Split('"')[3];
        }

if (geckoWebBrowser1.Document.GetElementById("delete_3_2") != null)
{
    MessageBox.Show("getelementbyid available!!!");
}