如何在 C# 中调用必应翻译函数

我写了一个地铁风格的应用程序来调用必应翻译器，但它不起作用。我尝试调试此程序，但 UI 没有响应。我无法确定是我正在使用的URI还是其他问题。

这是我的代码：

public string GetTranslatedText(string textToTranslate, string fromLang, string toLang)
{
    string translation;
    if (fromLang != toLang)
    {
        string uri = "http://api.microsofttranslator.com/v2/Http.svc/Translate?appId=" +
                    appID + "&text=" + textToTranslate + "&from=" + fromLang + "&to=" + toLang;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
        try
        {
            WebResponse response = request.GetResponse();
            Stream strm = response.GetResponseStream();
            StreamReader sr = new StreamReader(strm);
            translation = sr.ReadToEnd();
            response.Close();
            sr.Close();
        }
        catch (WebException)
        {
            MessageBox.Show("Ensure that you are connected to the internet.",
                        "Translator", MessageBoxButton.OK, MessageBoxImage.Stop);
            return (string.Empty);
        }
    }
    else
    {
        MessageBox.Show("Will not translate to the same language.", "Translator",
                    MessageBoxButton.OK, MessageBoxImage.Exclamation);
        return (string.Empty);
    }
    // Parse string into an XElement and get the XElement Value
    // which is returned as the translated text.
    return (XElement.Parse(translation).Value);
}