string yourStr = ....................;
Match m = Regex.Match(yourStr, @"<img[^>]*src=(['""])?[^'""\s>]*?(?<img>[^'""\s>/]*)\1[^>]*>", RegexOptions.IgnoreCase);
if (m.Success)
{
MessageBox.Show(m.Groups["img"].Value);
}
string yourStr = ....................;
Match m = Regex.Match(yourStr, @"<img[^>]*src=(['""])?(?<img>[^'""\s>]*)\1[^>]*>", RegexOptions.IgnoreCase);
if (m.Success)
{
MessageBox.Show(m.Groups["img"].Value);
}