您希望进度条具体反映什么？是下载文件（因为它很大）还是处理文件？
进度条反映处理文件
您的进度条不会改变，因为您的方法是同步的 - 在它结束时不会发生任何其他事情。 BackgroundWorker 类专为此类问题而设计。它以异步方式完成主要工作，并且能够报告进度已更改。以下是如何更改游览方式以使用它：
private void button1_Click(object sender, EventArgs e)
{
string text = textBox1.Text;
string url = "http://api.bing.net/xml.aspx?AppId=XXX&Query=" + text + "&Sources=Translation&Version=2.2&Market=en-us&Translation.SourceLanguage=en&Translation.TargetLanguage=De";
XmlDocument xml = new XmlDocument();
xml.Load(url);
XmlNodeList node = xml.GetElementsByTagName("tra:TranslatedTerm");
BackgroundWorker worker = new BackgroundWorker();
// tell the background worker it can report progress
worker.WorkerReportsProgress = true;
// add our event handlers
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(this.RunWorkerCompleted);
worker.ProgressChanged += new ProgressChangedEventHandler(this.ProgressChanged);
worker.DoWork += new DoWorkEventHandler(this.DoWork);
// start the worker thread
worker.RunWorkerAsync(node);
}
现在，主要部分：
private void DoWork(object sender, DoWorkEventArgs e)
{
// get a reference to the worker that started this request
BackgroundWorker workerSender = sender as BackgroundWorker;
// get a node list from agrument passed to RunWorkerAsync
XmlNodeList node = e.Argument as XmlNodeList;
for (int i = 0; x < node.Count; i++)
{
textBox2.Text = node[i].InnerText;
workerSender.ReportProgress(node.Count / i);
}
}
private void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// do something after work is completed
}
public void ProgressChanged( object sender, ProgressChangedEventArgs e )
{
progressBar.Value = e.ProgressPercentage;
}
反映下载文件的进度条
尝试使用HttpWebRequest 将文件作为流获取。
// Create a 'WebRequest' object with the specified url.
WebRequest myWebRequest = WebRequest.Create(url);
// Send the 'WebRequest' and wait for response.
WebResponse myWebResponse = myWebRequest.GetResponse();
// Obtain a 'Stream' object associated with the response object.
Stream myStream = myWebResponse.GetResponseStream();
long myStreamLenght = myWebResponse.ContentLength;
所以现在您知道了这个 XML 文件的长度。然后你必须从流中异步读取内容（BackgroundWorker 和StreamReader 是个好主意）。使用myStream.Position 和myStreamLenght 计算进度。
我知道我不是很具体，但我只是想为您指明正确的方向。我认为在这里写所有这些东西是没有意义的。这里有一些链接可以帮助您处理Stream 和BackgroundWorker：