WP7 网页控制字符编码

我有这一小段HTML

<b>OBNUBIL�,</b> 
<abbr class="abbrev" title="persoană">pers.</abbr>
 3 <i>obnubilează,</i> 
<abbr class="abbrev" title="verb">vb.</abbr>
 I. <abbr class="abbrev" title="reflexiv">Refl.</abbr> 
(Rar; despre vedere, memorie) A se �ntuneca, a slăbi, a se umbri.  Din 
<abbr class="abbrev" title="limba latină">lat.</abbr> 
<b>obnubilare,</b> 
<abbr class="abbrev" title="limba franceză">fr.</abbr> 
<b>obnubiler.</b>

我想在用 C# 编写的 Windows Phone 应用程序的 Web 浏览器中显示。这段 HTML 存储在一个字符串中：str2.我使用了这行代码：webBrowser1.NavigateToString(str2) .它有效，但未显示Romanian diacritics (ă ,ș ,ț,�, � ,Ă,Ț ,�,�,Ș)。
如何在 Windows Phone 中将 WebControl 的字符编码从 UTF-8 更改为 ISO-8859-16？

private void webClient_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    if (e.Error != null)
    {
        Deployment.Current.Dispatcher.BeginInvoke(() =>
        {
            // Showing the exact error message is useful for debugging. In a finalized application, 
            // output a friendly and applicable string to the user instead. 
            MessageBox.Show(e.Error.Message);
        });
    }
    else
    {
        string textString = (string)e.Result;
        string fixedString = "";
        // This search returns the substring between two strings, so 
        // the first index is moved to the character just after the first string.
        string defStart = "cuvânt'">";
        string defEnds = "</span>  <br/>";
        textString = textString.Replace("'r", "").Replace("'n", "");
        int first = textString.IndexOf(defStart) + defStart.Length;
        int last = textString.LastIndexOf(defEnds);
        string str2 =textString.Substring(first, last - first);
        str2 = str2.Replace("&#x2013;", " - ");
        // Remove tab spaces
        str2 = str2.Replace("'t", " ");
        // Remove multiple white spaces from HTML
        str2 = Regex.Replace(str2, "''s+", " ");
        //str2 = Regex.Replace(str2, "<[^>]+>", string.Empty);
        //BannerTextBlock.Text=str2;
        webBrowser1.NavigateToString(str2);
    }
}

我希望有人理解我的问题并可以帮助我。提前感谢！