Question

Everything works besides: links.Remove(linkToClick) since HtmlElementCollection doesn’t have a “Remove” method.

I recently asked a question here: How to have loop move to the next id available rather than doing the same continuously?

and that is what was recommended to me but I have been searching and trying to figure it out for the past two hours and still can’t figure it out.

HtmlElementCollection links = null;

private void button2_Click(object sender, EventArgs e)
{
    // This way you only get the links once.
    links = webBrowser1.Document.GetElementsByTagName("a");

    timer1.Start();
}

private void timer1_Tick(object sender, EventArgs e)
{
    HtmlElement linkToClick = null;

    foreach (HtmlElement link in links)
    {
        if (link.GetAttribute("id").Contains("user"))
        {
            linkToClick = link;
            break;
        }
    }

    // did I find a link?
    if (linkToClick != null)
    {
        // Remove it from the list so you don't click it again.
        links.Remove(linkToClick);

        link.InvokeMember("click");
    }
}

Answer 1

List<HtmlElement> links = null;

private void button2_Click(object sender, EventArgs e)
{
    // This way you only get the links once.
    links = new List<HtmlElement>(webBrowser1.Document.GetElementsByTagName("a")
                                                      .Cast<HtmlElement>());

    timer1.Start();
}

private void timer1_Tick(object sender, EventArgs e)
{
    HtmlElement linkToClick = null;

    foreach (HtmlElement link in links)
    {
        if (link.GetAttribute("id").Contains("user"))
        {
            linkToClick = link;
            break;
        }
    }

    // did I find a link?
    if (linkToClick != null)
    {
        // Remove it from the list so you don't click it again.
        links.Remove(linkToClick);

        linkToClick.InvokeMember("click");
    }
}

I would also suggest stopping the timer from within the timer if linkToClick == null, and why won’t you also FILTER the list in advance?

links = new List<HtmlElement>(webBrowser1.Document.GetElementsByTagName("a")
                                                  .Cast<HtmlElement>());

links.RemoveAll(link => !link.GetAttribute("id").Contains("user"));

And in timer:

if (links.Count > 0)
{
    links[0].InvokeMember("click");
    links.RemoveAt(0);
}
// else timer.Stop();