efficient way to find string with streamreader

Question

I get web response and use streamreader to obtain the response as a string

my code is

HttpWebResponse response = (HttpWebResponse) request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string strResponse = reader.ReadToEnd();

sample of string is

<div class="box-round">
<ol  style="list-style-type: decimal;list-style-position:outside;margin-left:42px;">
<li>Order ID #A123456 already exists: Update performed
</ol>
</div>

or

<div class="box-round">
    <ol  style="list-style-type: decimal;list-style-position:outside;margin-left:42px;">
    <li>New order created
    </ol>
</div>

I want to locate the following line within the string

Order ID #A123456 already exists: Update performed

or

New order created

Is this the best way to search for the line(s)

  while (!reader.EndOfStream)
    {
        line = reader.ReadLine();
        if (!string.IsNullOrEmpty(line))
        {

        }
    }

Answer 1

Well, personally I would use:

string line;

while ((line = reader.ReadLine()) != null)
{
    if (line.Contains(...))
    {
    }
}

Reading the line gives you the data and tells you whether you've reached the end of the stream. I agree with Jeff though - "parsing" HTML by reading it line by line is generally a bad idea. It may be good enough in your specific situation, of course.

Answer 2

Here's how to do it with regex, sure regex isn't the best method, but if this is a one time thing working with an html parser is probably more than you are bargaining for

Match myMatch = Regex.Match(input, 
       @"<div class=""box-round"">.*?<li>(.*?)</ol>", Regex.Singleline);

if (myMatch.Success)
{

}