C＃使用webclient和希伯来语获得奇怪的 符号

Question

我正在尝试获取网站的标题标记。有些东西是希伯来语，虽然大部分都是正确的希伯来语，但有时我会得到奇怪的符号： 。 我的代码：

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls
                                       | SecurityProtocolType.Tls11
                                       | SecurityProtocolType.Tls12
                                       | SecurityProtocolType.Ssl3;

var cookieContainer = new CookieContainer();
using (var web = new WebClientEx(cookieContainer))
{
    web.Headers["Accept"] = "*/*";
    web.Headers["User-Agent"] = ProxiesServersExtension.GetRandomUserAgent();
    web.Headers["Method"] = "GET";
    web.Headers["Content-Type"] = "text/html";
    web.Headers.Add("Accept-Language", "en-US,en;q=0.8");

    Uri myUri = new Uri(url, UriKind.Absolute);
    var page = web.DownloadStringAwareOfEncoding(myUri);

public static string DownloadStringAwareOfEncoding(this WebClient webClient, Uri uri)
{
    var rawData = webClient.DownloadData(uri);
    var encoding = WebUtils.GetEncodingFrom(webClient.ResponseHeaders, Encoding.UTF8);
    return encoding.GetString(rawData);
}

这是获取编码的函数：

 public static Encoding GetEncodingFrom(NameValueCollection responseHeaders, Encoding defaultEncoding = null)
        {
            if (responseHeaders == null)
                throw new ArgumentNullException("responseHeaders");

            //Note that key lookup is case-insensitive
            var contentType = responseHeaders["Content-Type"];
            if (contentType == null)
                return defaultEncoding;

            var contentTypeParts = contentType.Split(';');
            if (contentTypeParts.Length <= 1)
                return defaultEncoding;

            var charsetPart =
                contentTypeParts.Skip(1).FirstOrDefault(
                    p => p.TrimStart().StartsWith("charset", StringComparison.InvariantCultureIgnoreCase));
            if (charsetPart == null)
                return defaultEncoding;

            var charsetPartParts = charsetPart.Split('=');
            if (charsetPartParts.Length != 2)
                return defaultEncoding;

            var charsetName = charsetPartParts[1].Trim();
            if (charsetName == "")
                return defaultEncoding;

            try
            {
                return Encoding.GetEncoding(charsetName);
            }
            catch (ArgumentException ex)
            {
                throw new InvalidOperationException("The server returned data in an unknown encoding: " + charsetName, ex);
            }
        }